CVE-2026-80927 Linux CVE debrief

Who should care

Linux kernel developers, maintainers, and users who rely on the Linux kernel for their systems should assess their exposure and verify the presence of the fix in their kernel versions.

Why it matters

The vulnerability in the Linux kernel's timekeeping subsystem could potentially lead to the use of uninitialized stack data in calculations, indirectly leaking data to userspace. Linux kernel developers, maintainers, and users should assess their exposure and verify the presence of the fix in their kernel versions.

• Verify the configuration of the auxiliary clock to prevent potential data leaks
• Monitor system logs for potential exploitation attempts to detect possible malicious activity
• Review kernel version and check for the presence of the fix to ensure the vulnerability is patched

Technical summary

The Linux kernel's timekeeping subsystem has a vulnerability in the __do_adjtimex() function. The function did not check the return value of tk_get_aux_ts64(), potentially leading to the use of uninitialized stack data in calculations. This could indirectly leak data to userspace. The vulnerability has been resolved by adding a check for the return value of tk_get_aux_ts64(). Linux kernel developers, maintainers, and users should assess their exposure and verify the presence of the fix in their kernel versions to prevent potential data leaks and ensure the security of their systems.

Defensive priority

Linux kernel developers and maintainers should assess exposure and verify the presence of the fix in their kernel versions.

Recommended defensive actions

• Review kernel version and check for the presence of the fix
• Verify the configuration of the auxiliary clock
• Monitor system logs for potential exploitation attempts
• Perform a thorough review of system configurations and kernel versions to identify potential exposure
• Implement compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions and retest remediated assets to ensure the vulnerability is fully resolved
• Review and update asset inventory to reflect changes in system configurations and kernel versions

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, but do not specify affected or fixed kernel versions. The fix involves adding a check for the return value of tk_get_aux_ts64() in the __do_adjtimex() function.

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.