Vulnerability Management and more

August Microsoft Patch Tuesday. A total of 401 vulnerabilities were addressed - 170 fewer than in July. One of the vulnerabilities is known to be actively exploited in the wild: 🔻 EoP - Windows Ancillary Function Driver for WinSock (CVE-2026-68820). A local attacker can exploit this vulnerability to gain SYSTEM-level privileges. There is a contradiction in Microsoft's description: the Exploit Code Maturity in CVSS is marked as "Unproven", while at the same time Microsoft states that the vulnerability is being exploited in the wild. 🤷‍♂️ Public exploits are available for two other vulnerabilities: 🔸 EoP - Windows User Profile Service (CVE-2026-62832). This vulnerability allows an authenticated attacker to elevate privileges to ADMINISTRATOR level. Rapid7 believes this vulnerability is related to the LegacyHive exploit, which was published on July 14. 🔸 EoP - Windows Kernel (CVE-2026-62737). This vulnerability allows an authenticated attacker to elevate privileges to SYSTEM level. An exploit has been publicly available since August 11. Among the remaining vulnerabilities, the following stand out: 🔹 RCE - Windows DNS Server (CVE-2026-62878). This wormable vulnerability allows a remote unauthenticated attacker to execute code on a vulnerable server with elevated privileges. It is recommended to test and install the update as soon as possible, especially on Internet-facing DNS servers. 🔹 RCE - Windows Deployment Services TFTP Server (CVE-2026-62893). This vulnerability, discovered as part of the ZDI (Zero Day Initiative) program, allows an attacker to execute code without authentication or user interaction. TFTP has no authentication mechanism and is available remotely via UDP port 69. Any WDS server serving Windows Imaging Format (WIM) files via TFTP, which is the standard PXE boot scenario, is vulnerable. The issue results from the lack of validation of the existence of an object before performing operations on it. UDP port 69 should be blocked at the perimeter, but attackers could easily use this vulnerability for lateral movement within an organization. If you're using WDS for deployments, test and install this update quickly. 🔹 RCE - Windows DHCP Server (CVE-2026-62823). Successful exploitation of this vulnerability allows a remote unauthenticated attacker to execute arbitrary code from an adjacent network by sending a specially crafted packet that triggers a heap-based buffer overflow. 🔹 EoP - Microsoft Exchange (CVE-2026-62911). This vulnerability allows a remote authenticated attacker (with Privileges Required: Low according to CVSS) to gain control over the mailboxes of all Exchange users, send and read emails, and download attachments. This vulnerability was demonstrated at Pwn2Own Berlin. ZDI researchers provided Microsoft with working exploits. 🔹 RCE - Microsoft QUIC (CVE-2026-62815). This use-after-free vulnerability allows an unauthenticated attacker to execute arbitrary code on a target system by sending a specially crafted network packet. QUIC is an IETF-standardized transport protocol that runs over UDP instead of TCP and serves as the foundation for HTTP/3. The protocol is used by approximately 13.5 million websites. 🔹 Tampering - Windows Container Isolation FS Filter Driver (unionfs.sys) (CVE-2026-72971). This vulnerability reportedly allows an attacker to overwrite certain files. As a result, an attacker could perform an action within a container that could impact the host system. 🗒 Full Vulristics report @avleonovcom #Microsoft #Windows #PatchTuesday #DNS #DHCP #Exchange #QUIC #WindowsDeploymentServices #TFTP #WDS #PXE #WindowsKernel #Winsock #AFDsys #UserProfileService #ContainerEscape #ContainerSecurity #UnionFS #LegacyHive #ZDI #Pwn2Own #Rapid7 #Vulristics

I wonder how this typo even happened? 🤔 Does Microsoft actually fill in vulnerability descriptions manually every time, retyping the text from scratch? 🙄 Though I kind of like the word "Vulernability". It sounds like something related to the ability to learn.…

About Remote Code Execution - Microsoft SharePoint (CVE-2026-58644) vulnerability. Information about this vulnerability was published on July 14 as part of the July Microsoft Patch Tuesday. The vulnerability in Microsoft SharePoint Server, caused by a deserialization flaw (CWE-502), allows an attacker with Site Owner privileges or higher to inject and remotely execute arbitrary code on the SharePoint server. This can result in full server compromise, including the exfiltration of corporate documents and data, their modification or deletion, compromise of credentials accessible to the server, and further lateral movement into the organization's internal infrastructure. The authentication requirement, of course, makes exploitation of the vulnerability more difficult. However, an attacker could potentially leverage the previously disclosed EoP vulnerability CVE-2026-56164. At the same time, there is currently no confirmation that these vulnerabilities have been exploited together as part of a single attack chain. 👾 Microsoft experts flagged this vulnerability as being exploited in the wild on the day of Patch Tuesday. Two days later, on July 16, the vulnerability was added to the CISA KEV catalog. Details of the attacks are not yet known. 🛠 No public exploits have been observed so far. ⚙️ Updates are available for Microsoft SharePoint Server 2016, 2019, and Subscription Edition. @avleonovcom #Microsoft #SharePoint #KEV #CISAKEV #PatchTuesday #Deserialization

About Elevation of Privilege - Microsoft SharePoint (CVE-2026-56164) vulnerability. The vulnerability was disclosed in the July Microsoft Patch Tuesday release on July 14. The vulnerability, related to missing authentication for a critical function (CWE-306), allows an unauthenticated attacker to remotely elevate their privileges. It is quite interesting that the CVSS scores for the vulnerability differ significantly between Microsoft's website and the NVD. 🔹 Microsoft: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N (5.3 MEDIUM) 🔹 NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (9.8 CRITICAL) As can be seen, the difference is that Microsof's experts consider the impact of successful exploitation on integrity to be low, while the NVD rates the impact on confidentiality, integrity, and availability as high. This once again highlights the subjective nature of CVSS as a vulnerability prioritization tool. 😉 👾 Microsoft experts flagged this vulnerability as being exploited in the wild on the day of Patch Tuesday. The vulnerability was also added to the CISA KEV catalog on the same day. Microsoft credited Mandiant Incident Response for reporting this vulnerability, which suggests that Mandiant may have been involved in identifying the exploitation activity. There are currently no publicly available details regarding the attacks. However, according to Bleeping Computer, this vulnerability may have been exploited in an attack against the Swiss Federal Office of Information Technology, Systems and Telecommunication (BIT) reported on July 28. During the incident, credentials for around 200 user and technical accounts were compromised on Internet-facing SharePoint servers. The investigation did not reveal any other data breaches. According to BIT, SharePoint vulnerabilities from the July Microsoft Patch Tuesday were exploited on the servers, although the specific CVEs were not disclosed. 🛠 An exploit for the vulnerability has been available on GitHub since August 6. According to the exploit author's description, the vulnerability allows a remote unauthenticated attacker to elevate privileges to the level of Farm Administrator. By abusing request processing and routing mechanisms, an attacker can force a vulnerable server to fall back to an elevated security context instead of rejecting an unauthenticated request. This enables the attacker to access information about site collections, users, and server configuration, add administrators, and execute commands. ⚙️ Updates are available for Microsoft SharePoint Server 2016, 2019, and Subscription Edition. In addition to installing the updates, Microsoft experts recommend enabling the AMSI antimalware scanning interface on the server and setting the Request Body Scan mode to Full to reduce the risk of exploitation. @avleonovcom #Microsoft #SharePoint #CVSS #CISA #CISAKEV #NVD #Mandiant #AMSI #BleepingComputer #BIT

About Elevation of Privilege - NT OS Kernel (CVE-2026-42980) vulnerability. Information about this vulnerability was disclosed as part of the June Microsoft Patch Tuesday on June 9. The vulnerability was not specifically highlighted in Microsoft Patch Tuesday reviews published by VM vendors. This Microsoft Windows NT OS Kernel elevation of privilege vulnerability is caused by improper handling of integer values during data construction in the Windows Management Instrumentation (WMI) subsystem, resulting in an out-of-bounds write. Successful exploitation allows a local attacker with low privileges (a standard user account) to escalate privileges to NT AUTHORITY\SYSTEM. Obtaining NT AUTHORITY\SYSTEM privileges grants full control over the affected host, enabling an attacker to execute arbitrary commands, modify security settings, access protected data, and use the compromised host as a foothold for further lateral movement within the target environment. 🛠 On July 7, a detailed write-up describing the exploitation of this vulnerability was published. A public proof-of-concept (PoC) exploit is also available on GitHub. 👾 There is currently no evidence of in-the-wild exploitation of this vulnerability. @avleonovcom #Microsoft #Windows #WindowsKernel #NTOSKernel #WMI #KernelExploit #PrivilegeEscalation

About Remote Code Execution - ViPNet Client (BDU:2026-09885) vulnerability. The ViPNet Client software suite is designed to protect corporate users' workstations by providing secure data exchange over IP networks, controlling the network activity of applications and operating system components, and performing personal firewall functions (in the ViPNet Client for Windows version). ViPNet Client operates within the ViPNet network ecosystem and integrates with products from the ViPNet Network Security product line. A vulnerability involving a violation of the data protection mechanism (CWE-693) allows an attacker who has gained control of a host running ViPNet Administrator to distribute malicious updates to hosts running ViPNet Client. According to the vendor bulletin, the attackers' objectives include compromising the integrity of the operating environment, escalating privileges, and executing arbitrary code on the system. 👾 On July 16, experts from Positive Technologies reported the exploitation of this vulnerability in the wild. During the attacks, the threat actor transmitted a container file (.ctl) containing the malicious wtsapi32.dll library using the built-in functionality of the MFTP transport protocol. The malicious library was loaded by the Itcsrvup64.exe executable (a component of the ViPNet software update service) using the DLL Hijacking technique and written to the file system through a Path Traversal technique. The research describes various types of malware deployed by the threat actors on compromised hosts, including tools that operate as proxy servers to redirect network traffic, load additional DLL libraries into process memory and execute them, clear InfoTeCS logs, and collect system information (processes, network connections, installed software, etc.). The report also mentions the previously described Donnect loader and ShadowRelay backdoor. According to available data, the attack campaign was active from at least June 1 to July 14, 2026, and affected at least eight organizations. ⚙️ To remediate the vulnerability, certified builds must be updated to ViPNet Client 4 version 4.5.3 (build 65211) or later. For release builds, ViPNet Client 4 must be updated to version 4.5.5 (build 24749) or later. The vendor also recommends updating ViPNet Administrator 4 to version 4.6.11.5114. 🛠 No signs of publicly available exploits for this vulnerability have been observed so far. @avleonovcom #ViPNet #ViPNetClient #ViPNetAdministrator #InfoTeCS #MFTP #DLLHijacking #PathTraversal #Itcsrvup64exe #wtsapi32dll #Donnect #ShadowRelay #PositiveTechnologies #PTESC

July Linux Patch Wednesday. A total of 2,017 vulnerabilities were addressed (539 in the Linux kernel and 504 in Chromium). For comparison, there were 1,888 vulnerabilities in June. Once again, a new record. Moreover, next month will most likely set another record, as 1,704 vulnerabilities have already been addressed 2.5 weeks before the August LPW. 🤷‍♂️ But for now, let's take a closer look at the July report. Only one vulnerability shows signs of exploitation in the wild: 🔻 RCE - Gogs (CVE-2025-8110). Gogs is a self-hosted web service for managing Git repositories, similar in purpose to GitHub or GitLab. An attacker can achieve remote code execution by manipulating the .git/config file through symbolic link bypasses and injecting commands via sshCommand. Multiple public exploits are available on GitHub. The vulnerability has been added to the CISA KEV catalog. There are also 178 vulnerabilities with public exploits available or indications that they exist, but there are currently no signs of exploitation in the wild. For comparison, last month there were 109 such vulnerabilities. Among them, the following stand out: 🔸 RCE - NGINX (CVE-2026-42533). NGINX is a web server and software for handling network requests, which is often used as a reverse proxy, load balancer, and gateway for web applications. An unauthenticated attacker can exploit this vulnerability for remote code execution by sending crafted HTTP requests.🔸 RCE - libssh2 (CVE-2026-55200). libssh2 is a C library that implements the SSH-2 protocol and allows applications to establish secure SSH connections, execute commands, and transfer files via SFTP/SCP. A remote attacker can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution. 🔸 RCE - Linux Kernel "RefluXFS" (CVE-2026-64600). An attacker with an ordinary local account can exploit the vulnerability to overwrite protected files on disk and gain root privileges on affected systems, including installations running SELinux in Enforcing mode. In practice, the vulnerability allows an attacker to set an empty root password. 🔸 RCE - Gogs (CVE-2025-64111). Due to an insufficient patch for CVE-2024-56731, it is still possible to modify files in the .git directory and achieve remote command execution. Based on the exploit code, authentication is required for exploitation. 🔸 CodeInj - MediaWiki (CVE-2026-58025). MediaWiki is a free and open-source web platform for creating and managing wiki websites, powering Wikipedia and other collaborative content editing projects. An attacker with the importupload or import permission (default: sysop group) can craft a malicious XML import file containing serialized PHP objects in params fields, triggering arbitrary object instantiation and potentially leading to remote code execution through gadget chains. 🔸 RCE - FFmpeg (CVE-2026-8461). FFmpeg is a free and open-source collection of libraries and utilities for processing audio and video data. An out-of-bounds write vulnerability in FFmpeg's libavcodec library, specifically in the MagicYUV decoder, allows denial-of-service and, in some cases, can be exploited for remote code execution. [ Read the full post on avleonov.com ] 🗒 Full Vulristics report @avleonovcom #LinuxPatchWednesday #Vulristics #Linux #LinuxKernel #Chromium #CISAKEV #Gogs #NGINX #libssh2 #MediaWiki #FFmpeg #7Zip

July Microsoft Patch Tuesday. In the second week of July, I was on vacation in St. Petersburg. After that, I got caught up with a bunch of other tasks, so I'm only publishing this roundup now. Better late than never, especially considering how unusual this MSPT turned out to be. 😉 In total, 571 vulnerabilities were addressed - almost three times (❗️) more than in June. There are four vulnerabilities that have been reported as exploited in the wild: 🔻 RCE - Microsoft SharePoint (CVE-2026-58644). An attacker with Site Owner privileges or higher can remotely inject and execute arbitrary code on the SharePoint Server. 🔻 RCE - Microsoft SharePoint (CVE-2026-50522). The vulnerability description is identical to CVE-2026-58644. According to ZDI, the CVE-2026-50522 vulnerability was successfully demonstrated at Pwn2Own Berlin. Despite this, Microsoft rates its Exploit Maturity as "Unknown", even though researchers have already provided a working exploit to the company. This once again shows that organizations should not rely solely on software vendors' assessments and should instead perform their own risk evaluation. If you have Internet-facing SharePoint servers, you should test and deploy the patch addressing this vulnerability as soon as possible. 🔻 EoP - Microsoft SharePoint Server (CVE-2026-56164). Missing authentication for a critical function in Microsoft Office SharePoint could allow an unauthenticated attacker to elevate privileges over a network. Microsoft mentioned in the advisory that enabling the Antimalware Scan Interface (AMSI) on the server and setting the Request Body Scan mode to Full can help mitigate this flaw. 🔻 EoP - Active Directory Federation Services (CVE-2026-56155). Insufficient granularity of access control (CWE-1220) in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally. An attacker who successfully exploited this vulnerability could gain administrator privileges. There are eight more vulnerabilities with publicly available exploits: 🔸 EoP - Windows User Interface Core (CVE-2026-50454). Relative path traversal (CWE-23) allows an authorized attacker to elevate privileges locally. An attacker who successfully exploited this vulnerability could gain SYSTEM privileges. The PoC starts from a normal, non-elevated process belonging to a local administrator and opens an interactive command prompt as NT AUTHORITY\SYSTEM. 🔸 EoP - Windows WalletService (CVE-2026-49176). Improper privilege management (CWE-269) allows an authorized attacker to elevate privileges locally. The exploit PoC starts a command prompt as SYSTEM in the active desktop session. 🔸 RCE - Microsoft Message Queuing Queue Manager (CVE-2026-54992). The existing exploit PoC demonstrates denial of service; it does not demonstrate code execution. [ Read the full post on avleonov.com ] 🗒 Full Vulristics Report @avleonovcom #Vulristics #PatchTuesday #Microsoft #MSPT #SharePoint #Exchange #Windows #ActiveDirectory #RDP #WSUS #Dynamics365 #Azure #SharePointServer #ADFS #UICore #WalletService #MSMQ #NarratorBraille #CloudFiles #Win32k #WindowsKernel #AzureSpringApps #SpringCloudAzureB2C #DynamicsNAV #BusinessCentral #HyperV #OWA #DHCPServer #DHCPClient #WAC #FTPService #GDIPlus #NetworkDriver #ADDS #RDC #TCPIP #PrintSpooler #RMCAST #RMT #SQLServer #Copilot #WindowsUpdate #ADCS #AoE2 #AoE2DE #Chrome #Discord #Explorer #Spotify #ESXi

I wonder how this typo even happened? 🤔 Does Microsoft actually fill in vulnerability descriptions manually every time, retyping the text from scratch? 🙄 Though I kind of like the word "Vulernability". It sounds like something related to the ability to learn. 😅 If anyone's working on an educational project related to vulnerabilities, consider this a hint. 😉 @avleonovcom

July "In the Trend of VM" (#29): Microsoft Exchange Server vulnerability. Here is my traditional monthly roundup of trending vulnerabilities, according to Positive Technologies. The previous June edition featured four vulnerabilities. This time, there's only one. 🗞 Post on Habr (rus) 🗒 Digest on the PT website (rus) 🔻 XSS - Microsoft Exchange (CVE-2026-42897). The vulnerability allows attackers to execute arbitrary JavaScript in a user's browser when the user opens a malicious email in Outlook Web Access (OWA). A public proof-of-concept exploit is available, and the vulnerability has already been exploited in the wild. 🟥 The full list of trending vulnerabilities is available on the portal @avleonovcom #PositiveTechnologies #TrendVulns #Microsoft #Exchange #Outlook #OWA #XSS #Spoofing #JavaScript #InternetExplorer #Edge #CISA #CISAKEV #KEV #exploit #GitHub #EM #EOMT #ESU

About Cross Site Scripting - Microsoft Exchange (CVE-2026-42897) vulnerability. The vulnerability was fixed on May 14 outside the regular Microsoft Patch Tuesday cycle. Improper neutralization of input during web page generation (CWE-79, XSS) in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network. In practical terms, this means that a remote attacker could exploit this vulnerability by sending a specially crafted email to a user. If the user opens the email in Outlook Web Access and certain interaction conditions are met, arbitrary JavaScript can be executed in the browser context. As a result, the attacker may gain control of the user's mailbox by using an active user session. 👾 Microsoft experts immediately reported signs of active exploitation in the wild for this vulnerability. The vulnerability was added to the CISA KEV on May 15. ⚒️ A public exploit for the vulnerability was published on GitHub on May 15 as well. ⚙️ Initially, mitigation measures were recommended to address the vulnerability, delivered via the Exchange Emergency Mitigation (EM) service or by using the Exchange on-premises Mitigation Tool (EOMT) script. Security updates that fix the vulnerability in Microsoft Exchange Server Subscription Edition RTM, Exchange Server 2016, and Exchange Server 2019 were released almost a month later, on June 9. Microsoft experts recommended keeping the mitigations enabled even after applying the patch, as they provide an additional layer of protection. However, applying these mitigations may cause issues (for example, errors when printing calendars and displaying images in OWA). ⚠️ Please note that Exchange Server 2016 and 2019, which are out of support, are also affected by this vulnerability. Only customers enrolled in the Period 2 Extended Security Update (ESU) program are eligible to receive Exchange Server 2016 and 2019 security updates released between May and October 2026. @avleonovcom #Microsoft #Exchange #Outlook #OWA #XSS #Spoofing #JavaScript #InternetExplorer #Edge #CISA #CISAKEV #KEV #exploit #GitHub #EM #EOMT #ESU

June Linux Patch Wednesday. A total of 1,888 vulnerabilities (324 in the Linux kernel, and a whopping 728 in Chromium ❗️). For comparison, there were 1,638 vulnerabilities in May. The increase isn't as dramatic as it was from April to May, but it's still a new record. One of the vulnerabilities has been flagged as actively exploited in the wild: 🔻 RCE - Chromium (CVE-2026-11645). Chromium is the open-source web browser project that serves as the foundation for many modern browsers, including Google Chrome, Microsoft Edge, Brave, Opera, and Vivaldi. A publicly available Metasploit module exploits a vulnerability in the web browser's V8 JavaScript engine. The vulnerability is triggered by a specific code pattern that causes type confusion between internal V8 objects, resulting in out-of-bounds memory access. Successful exploitation may lead to remote code execution in the context of the browser process. There are also 109 vulnerabilities with public exploits or evidence that exploits exist, although there are no signs of active exploitation in real-world attacks yet. Among them, the following stand out: 🔸 EoP - Linux Kernel "CIFSwitch" (CVE-2026-46243). This vulnerability could allow attackers to forge CIFS authentication key descriptions, abuse the kernel's key request mechanism, and gain root privileges. 🔸 EoP - Linux Kernel "PinTheft" (CVE-2026-43494). On a successfully exploited configuration, the chain completes and hands off to the discovered SUID binary with an overwritten first page - yielding a root shell if the race and kernel state align. 🔸 RCE - Apache ActiveMQ (CVE-2026-42588). ActiveMQ is an open-source message broker written in Java. Exploitation of this vulnerability requires valid credentials for the ActiveMQ Web Console. However, the default credentials are admin/admin. 🔸 InfDisc - Squid "Squidbleed" (CVE-2026-47729). Squid is an open-source caching proxy server. The vulnerability causes Squid's FTP parser to read beyond the boundary of a memory buffer, into a region that may contain a previous user's uncleared HTTP request data. 🔸 AuthBypass - Nextcloud (CVE-2026-45156). Nextcloud is an open source content collaboration platform. A missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. 🔸 XSS - Nextcloud (CVE-2025-59788). A vulnerability in a reachable files_pdfviewer example directory in Nextcloud allows attackers to execute arbitrary JavaScript in the context of a user's browser via a crafted PDF file to viewer.html. 🔸 XSS - Roundcube (CVE-2026-48849). Roundcube is a free, open-source webmail application. An unsanitized subject field in the draft restored value could lead to stored XSS/HTML/CSS injection on shared mailboxes. 🔸 DoS - ImageMagick (CVE-2026-46522). ImageMagick is an open-source image processing tool used to create, edit, and convert images. Due to a missing check in the MIFF decoder, a crafted file could cause an infinite loop resulting in CPU exhaustion. 🗒 Full Vulristics report @avleonovcom #LinuxPatchWednesday #LinuxKernel #Chromium #Metasploit #CIFSwitch #PinTheft #ApacheActiveMQ #JavaScript #Squid #Nextcloud #HTML #pdf #Roundcube #Email #ImageMagick #exploit #webbrowser #MIFF #ID4me #SUID #V8

June Microsoft Patch Tuesday. Last week I was on vacation in Veliky Novgorod, so I'm publishing this overview only now. A total of 202 vulnerabilities were addressed, approximately twice as many as in May. There are currently no vulnerabilities marked as exploited in the wild. However, there are two vulnerabilities with publicly available exploits: 🔸 RCE - HTTP.sys (CVE-2026-47291). This critical vulnerability allows remote, unauthenticated attackers to execute arbitrary code on affected systems without user interaction. However, systems using the default MaxRequestBytes registry value in the Windows HTTP stack are not affected. If needed, you can change this registry setting to protect systems while testing and deploying the patch. Microsoft's security bulletin includes instructions and a PowerShell script for this workaround. 🔸 DoS - HTTP.sys (CVE-2026-49160). The same exploit is used as for the previous RCE vulnerability. It is also worth paying attention to vulnerabilities that Microsoft has flagged as having a publicly available exploit: 🔹 SFB - Windows BitLocker (CVE-2026-50507). A successful attacker could bypass the BitLocker Device Encryption feature on the system storage device. An attacker with physical access to the target could exploit this vulnerability to gain access to encrypted data. According to Tenable, this is the "Bitskrieg" vulnerability discovered by the researcher known as Chaotic Eclipse/Nightmare Eclipse. 🔹 SFB - Secure Boot (CVE-2026-48570). An attacker who successfully exploited this vulnerability could bypass Secure Boot. This vulnerability was reported by Alon Leviev (STORM), who is known for previous research related to BootKitty and BlackLotus. Among the remaining vulnerabilities, the following are worth highlighting: 🔹 RCE - Windows Kernel (CVE-2026-45657). This vulnerability allows remote, unauthenticated attackers to run code with SYSTEM privileges without any user interaction. In other words, it could be used to spread automatically between systems. The issue is caused by how the Windows kernel processes TCP/IP traffic. Microsoft rated this as "Exploitation Less Likely", but security researchers and exploit developers are already analyzing the patch and trying to build an exploit. Test and deploy this patch as soon as possible. 🔹 EoP - Windows Collaborative Translation Framework (CTFMON) (CVE-2026-45586). This vulnerability affects a component used for voice and handwriting recognition. If exploited, an attacker could gain SYSTEM privileges. Microsoft rates this vulnerability as "Exploitation More Likely". 🔹 RCE - Windows Remote Desktop Client (CVE-2026-42909, CVE-2026-42913, CVE-2026-42985, CVE-2026-42992, CVE-2026-42993, CVE-2026-44799, CVE-2026-44801, CVE-2026-47289, CVE-2026-47653, CVE-2026-47654, CVE-2026-48563). Successful exploitation would require a victim to connect to an attacker-controlled server using an affected version of the Remote Desktop Client. This action could trigger a heap-based buffer overflow, resulting in remote code execution. 🔹 RCE - DHCP Client Service (CVE-2026-44815). This vulnerability allows remote, unauthenticated attackers to execute code on affected systems without user interaction. Because the DHCP client is widely enabled across Windows systems, this vulnerability presents a broad attack surface. Organizations should prioritize testing and deploying the patch for this vulnerability as soon as possible. 🗒 Full Vulristics report @avleonovcom #Microsoft #PatchTuesday #Vulristics #Windows #WindowsKernel #SecureBoot #BitLocker #RCE #DoS #EoP #RDP #RemoteDesktop #DHCP #HTTPsys #TCPIP #exploit #CTFMON #PrivilegeEscalation #STORM #Bitskrieg #ChaoticEclipse #NightmareEclipse

June "In the Trend of VM" (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities. Presenting the traditional monthly roundup of trending vulnerabilities according to Positive Technologies. In the previous May edition, we covered four vulnerabilities. This time, there are also four vulnerabilities associated with five CVE identifiers. 🗞 Post on Habr (rus) 🗒 Digest on the PT website (rus) 🔻 EoP - Linux Kernel "Dirty Frag" (CVE-2026-43284, CVE-2026-43500). A chain of vulnerabilities with a public exploit to obtain root access. There are signs of in-the-wild exploitation. 🔻 EoP - Linux Kernel "Fragnesia" (CVE-2026-46300). Another vulnerability for gaining root access with a public exploit. 🔻 EoP - Microsoft Defender "RedSun" (CVE-2026-41091). A privilege escalation vulnerability leading to SYSTEM-level access, with a public exploit available and indications of in-the-wild exploitation. Pay special attention to Windows server and desktop environments where Microsoft Defender is enabled but there is no Internet access for regular updates. 🔻 RCE - PAN-OS (CVE-2026-0300). An unauthenticated RCE with root privileges affecting PA-Series and VM-Series firewalls. A public exploit exists, and there are indications of in-the-wild exploitation. 🟥 The full list of trending vulnerabilities is available on the portal @avleonovcom #PositiveTechnologies #TrendVulns #DirtyFrag #HyunwooKim #v4bel #LinuxKernel #KernelExploit #xfrmESP #RxRPC #AppArmor #Linux #Ubuntu #RHEL #openSUSE #CentOSStream #AlmaLinux #Fedora #Fragnesia #V12 #Kernel #EoP #LPE #Microsoft #MicrosoftDefender #Defender #Windows #AntiMalware #exploit #GitHub #CISAKEV #KEV #NightmareEclipse #RedSun #PaloAlto #PANOS #NGFW #Firewall #Exploit #Shodan #PrismaAccess #CloudNGFW #Panorama

About Elevation of Privilege - Microsoft Defender "RedSun" (CVE-2026-41091) vulnerability. Microsoft Defender is a built-in security solution developed by Microsoft to protect the Windows operating system and user data from viruses, malware, and other cyber threats in real time. An improper link resolution vulnerability prior to file access ("link following", CWE-59) in Microsoft Defender, specifically within the Malware Protection Engine component, allows an authenticated local attacker to escalate privileges to SYSTEM level. As a result, an attacker could gain full control over the affected system, including unrestricted access to data, the ability to modify system settings, install software, manage user accounts, and disable security protections. 🛠 An exploit for the vulnerability was published on GitHub by security researcher Nightmare Eclipse on April 15, alongside exploits targeting other Windows component vulnerabilities. The account was later removed by GitHub administrators; however, this did not prevent the exploit code from spreading further. ⚙️ The security advisory and patches were released on May 19 outside Microsoft's regular Patch Tuesday schedule. Versions of Microsoft Malware Protection Engine from 1.1.26030.3008 through 1.1.26040.8 are affected. Systems with Microsoft Defender disabled are not vulnerable. By default, Microsoft Defender automatically updates Windows security components, antivirus definitions, and Microsoft Malware Protection Engine, so no additional user action is typically required. Malware Protection Engine is updated monthly or as new threats emerge, while antivirus definitions are updated several times per day. Update checks may run automatically anywhere from once to several times daily when an Internet connection is available. Manual update checks are also supported. 👾 According to Microsoft, the vulnerability is being exploited in the wild. The vulnerability was added to the CISA KEV catalog on May 20. 💡 Special attention should be paid to server and desktop Windows hosts where Microsoft Defender is not disabled, but Internet access is unavailable for regular updates. @avleonovcom #Microsoft #MicrosoftDefender #Defender #Windows #AntiMalware #exploit #GitHub #CISAKEV #KEV #NightmareEclipse #RedSun

About Elevation of Privilege vulnerability - Linux Kernel "Dirty Frag" (CVE-2026-43284, CVE-2026-43500) vulnerability. According to information from researcher Hyunwoo Kim (@v4bel), Dirty Frag is a vulnerability (a class of vulnerabilities) that allows a local…

About Remote Code Execution - PAN-OS (CVE-2026-0300) vulnerability. PAN-OS is an operating system for Palo Alto Networks firewalls and security platforms. User-ID™ Authentication Portal (also known as Captive Portal) is a non-default PAN-OS feature used to map IP addresses to usernames. By exploiting a buffer overflow vulnerability (CWE-787), an unauthenticated remote attacker can send specially crafted packets to a device with the Authentication Portal enabled, achieving arbitrary code execution with root privileges on the affected device. No authentication or user interaction is required. If the vulnerability is successfully exploited, the attacker gains full control over network traffic: they can intercept, modify, or block connections, access sensitive data, bypass security policies, hide traces of compromise, install backdoors, and use the device as a foothold for attacks on internal infrastructure. ⚙️ The vendor security advisory was published on May 6. PA-Series and VM-Series firewalls are affected. Prisma Access, Cloud NGFW, and Panorama appliances are not impacted by this vulnerability. Security updates for affected devices became available on May 13. As a workaround, the vendor recommended restricting User-ID™ Authentication Portal access to only trusted internal zones or disabling the User-ID™ Authentication Portal entirely if it is not required. 👾 On the same day, May 6, researchers from Palo Alto Networks Unit 42 published a report on active exploitation of the vulnerability in the wild. Post-exploitation activity includes deployment of publicly available tunneling tools (EarthWorm, ReverseSocks5), Active Directory enumeration using credentials likely obtained from the firewall, and systematic destruction of logs and other evidence of compromise. On the same day, the vulnerability was added to the CISA KEV catalog. 🛠 A public exploit was also published on GitHub on May 6. 🌐 PAN-OS is among the most widely deployed enterprise firewall operating systems in the world. As of June 5, Shodan identifies approximately 135,755 internet-facing PAN-OS instances, representing a significant attack surface. @avleonovcom #PaloAlto #PANOS #NGFW #Firewall #Exploit #CISAKEV #Shodan #PrismaAccess #CloudNGFW #Panorama

May Linux Patch Wednesday. A total of 1,638 vulnerabilities (474 in the Linux kernel). For comparison, in April there were 1,035 vulnerabilities (a record!). And this time it turns out to be a record again, more than one and a half times higher! The acceleration is both impressive and alarming. But we will see what happens next. At some point it should stabilize. Although the number of critical vulnerabilities is already so high that reviewing all of them becomes quite problematic. For 7 vulnerabilities there are signs of exploitation in the wild. And for another 264 there are public exploits. [ Read the full post on avleonov.com ] 🗒 Full Vulristics report @avleonovcom #LinuxPatchWednesday #Linux #LinuxKernel #CISAKEV #VulnCheckKEV #KEV #Exploit #Apache #ApacheHTTPServer #ApacheTomcat #ApacheActiveMQ #NGINX #ProFTPD #PgBouncer #Rclone #Postorius #GNUMailman #PostgreSQL #PHP #Composer #Django #Qualys #PackageKit #DirtyFrag #CopyFail #DirtyDecrypt #Fragnesia

About Elevation of Privilege - Linux Kernel "Fragnesia" (CVE-2026-46300) vulnerability. The vulnerability was discovered by researcher William Bowling together with the V12 team. Fragnesia belongs to the class of Dirty Frag vulnerabilities. It is an error in the ESP/XFRM subsystem, distinct from Dirty Frag, which was addressed with a separate patch. It allows achieving arbitrary byte writes into the kernel page cache of read-only files, without requiring any race condition. 🛠 Technical details and exploit code were published on May 15. The public exploit modifies the contents of /usr/bin/su in the kernel page cache, and then executes /usr/bin/su, resulting in the user obtaining a root shell. The on-disk binary is never modified. A reboot or cache flush restores normal system behavior. [ Read the full post on avleonov.com ] @avleonovcom #Linux #LinuxKernel #Fragnesia #V12 #DirtyFrag #Ubuntu #Kernel #EoP #LPE #xfrmESP

May "In the Trend of VM" (#27): high-profile vulnerabilities in Linux, ActiveMQ, SharePoint, and Adobe Acrobat Reader. While the previous April edition featured only one vulnerability, this one includes four, covering different technologies and attack scenarios. 🗞 Post on Habr (rus) 🗒 Digest on the PT website (rus) 🔻 EoP - Linux Kernel "Copy Fail" (CVE-2026-31431). The vulnerability allows an attacker to gain root privileges. 🔻 RCE - Apache ActiveMQ (CVE-2026-34197). A vulnerability in a solution widely used in enterprise systems and integration platforms. 🔻 Spoofing - Microsoft SharePoint Server (CVE-2026-32201). A vulnerability in a Microsoft collaboration and document management platform widely used in enterprise systems and internal portals. 🔻 RCE - Adobe Reader (CVE-2026-34621). A vulnerability in a widely used PDF document viewer; actively exploited in phishing attacks. 🟥 The full list of trending vulnerabilities is available on the portal @avleonovcom #PositiveTechnologies #TrendVulns