CVE-2026-52924 Linux CVE debrief

Who should care

This vulnerability affects Linux kernel users, particularly those using SCTP. System administrators, Linux kernel developers, and users of Linux-based systems should be aware of this vulnerability and take necessary actions to mitigate it. The vulnerability can be exploited remotely, and its high CVSS score indicates a significant risk to affected systems.

Technical summary

The vulnerability is caused by a use-after-free condition in the SCTP implementation of the Linux kernel. Specifically, when handling stale COOKIE-ECHO messages, the association is rolled back from COOKIE_ECHOED to COOKIE_WAIT, and user data may already have been queued and bundled with the COOKIE-ECHO chunk. This can lead to a use-after-free condition in the stream scheduler dequeue paths, resulting in a system crash or potentially allowing an attacker to execute arbitrary code. The fix involves fully purging the association outqueue when handling the Stale Cookie case.

Defensive priority

High priority should be given to patching this vulnerability, as it has a high CVSS score and can be exploited remotely. Linux kernel users should update their kernels to the latest version that includes the fix.

Recommended defensive actions

• Apply the official patch from the Linux kernel maintainers.
• Update Linux kernel to the latest version that includes the fix.
• Review system configurations and ensure that SCTP is not exposed to untrusted networks.
• Monitor system logs for potential exploitation attempts.
• Consider implementing additional security controls, such as network segmentation and access controls.

Evidence notes

The vulnerability was reported by Yuqi and fixed by the Linux kernel maintainers. The fix involves fully purging the association outqueue when handling the Stale Cookie case. The vulnerability has a CVSS score of 9.8 and is considered CRITICAL.

Official resources