CVE-2026-53162 Linux CVE debrief

Who should care

System administrators and security teams responsible for Linux kernel-based systems should be aware of this vulnerability. The vulnerability's impact is limited to systems using the Linux kernel with memcg enabled. The vulnerability's CVSS score is 7.8, indicating a high severity level.

Technical summary

The vulnerability is caused by the use of get_random_u32_below() in the nmi context, which is not reentrant- or NMI-safe. This can lead to corruption of the ChaCha batch state. The vulnerability has been resolved by replacing the random pick with a per-cpu round-robin counter stored in memcg_stock_pcp and serialized by the same local_trylock that already guards cached[] and nr_pages[]. This change ensures that the memcg_stock local_trylock prevents re-entry on the percpu stock itself, protecting against unrelated subsystem per-cpu lock corruption.

Defensive priority

High priority should be given to patching affected Linux kernel systems, as the vulnerability has a high CVSS score and can potentially lead to system crashes or unexpected behavior.

Recommended defensive actions

• Patch affected Linux kernel systems as soon as possible.
• Review system configurations to ensure memcg is enabled and properly configured.
• Monitor system logs for any unusual activity related to memcg charge draining.
• Consider implementing compensating controls, such as additional logging or monitoring, to detect potential issues.
• Verify that all necessary security updates are applied to the Linux kernel.

Evidence notes

The vulnerability was reported by Harry Yoo and resolved by replacing the random pick with a per-cpu round-robin counter. The vulnerability's CVSS score is 7.8, indicating a high severity level. The vulnerability's impact is limited to systems using the Linux kernel with memcg enabled.

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.