CVE-2026-52927 Linux CVE debrief

Who should care

Linux kernel users and administrators should be aware of this vulnerability and take steps to mitigate it. This vulnerability can be exploited by an attacker with local access to the system, and it is recommended to update the Linux kernel to the latest version as soon as possible. Additionally, users can consider implementing compensating controls such as monitoring and intrusion detection systems to detect potential exploitation attempts.

Technical summary

The vulnerability is caused by an out-of-bounds read in the compat_mtw_from_user function, which is part of the netfilter ebtables in the Linux kernel. The function is responsible for converting ebtables extensions from 32-bit user structures to kernel native structures. However, it lacks proper validation of the user-supplied match_size/target_size, leading to an out-of-bounds read as reported by KASAN. The fix introduces a check to ensure match_size is at least as large as the extension's required compatsize. This vulnerability can be exploited by an attacker with local access to the system, and it is recommended to update the Linux kernel to the latest version as soon as possible.

Defensive priority

High priority should be given to patching this vulnerability, as it can be exploited by an attacker with local access to the system. Linux kernel users and administrators should update the Linux kernel to the latest version as soon as possible to mitigate this vulnerability.

Recommended defensive actions

• Update the Linux kernel to the latest version
• Implement compensating controls such as monitoring and intrusion detection systems
• Review and update Linux kernel configurations to ensure they are secure
• Consider implementing additional security measures such as SELinux or AppArmor
• Monitor system logs for potential exploitation attempts

Evidence notes

The CVE-2026-52927 vulnerability was reported by Luxiao Xu and is related to the netfilter ebtables in the Linux kernel. The vulnerability has a CVSS score of 7.8 and is considered HIGH severity. The CVE was published on 2026-06-24T08:16:22.810Z and modified on 2026-06-28T08:16:24.193Z. The fix introduces a check to ensure match_size is at least as large as the extension's required compatsize.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.