Tag Archives: V12

June "In the Trend of VM" (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities

June In the Trend of VM (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities

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

About Elevation of Privilege - Linux Kernel "Fragnesia" (CVE-2026-46300) vulnerability

About Elevation of Privilege - Linux Kernel Fragnesia (CVE-2026-46300) vulnerability

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.

⚙️ Fragnesia affects the same kernel versions as Dirty Frag. Any distribution shipping a kernel without the May 13 patch is vulnerable. The vulnerability was confirmed on Ubuntu 6.8.0-111-generic (April 11, 2026 build). Monitor kernel package updates for your Linux distribution(s).

For systems where a kernel update is not possible, the same workaround as for Dirty Frag is effective (blacklisting modules). Systems where the Dirty Frag workaround has already been applied are already protected against Fragnesia. Systems that only received Dirty Frag updates without applying the workaround remain vulnerable and require new updates addressing Fragnesia.