Description
In the Linux kernel, the following vulnerability has been resolved:

timekeeping: Check the return value of tk_get_aux_ts64 in __do_adjtimex()

If the auxiliary clock is disabled during tk_get_aux_ts64() but is enabled
before tks->clock_valid is checked, then uninitialized stackdata will be
used in the calculations and indirectly leaked to userspace.

The same race window also exists after this change and also for the core
timekeeper. But in these cases the only effect would be incorrect
adjustments and this is userspace's responsibility to avoid this.
Published: 2026-09-11
Score: 2.8 Low
EPSS: < 1% Very Low
KEV: No
Impact: Information Leak
Action: Apply Patch
AI Analysis

Impact

The Linux kernel bug is triggered when the auxiliary clock is disabled during the tk_get_aux_ts64() call but enabled again before the tks->clock_valid field is examined. This race condition causes uninitialized stack data to be involved in time calculations, which can indirectly leak data to userspace. The same race window also exists after the change in the core timekeeper, but the only effect there is incorrect time adjustments, which userspace must handle. Consequently, the primary security impact of the vulnerability is an information leak through uninitialized data, not code execution or denial of service.

Affected Systems

All Linux kernel builds that contain the unpatched tk_get_aux_ts64 logic are affected. Because the applies to any kernel in which the described race condition still exists.

Risk and Exploitability

With a CVSS score of 2.8, the vulnerability is considered low severity. The EPSS score is < 1%, and the vulnerability is not listed initation would require a local attacker who can manipulate the auxiliary clock timing to create the race condition, making it a relatively narrow attack vector that does not provide remote or privilege escalation capabilities.

Generated by OpenCVE AI on September 21, 2026 at 03:16 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade the Linux kernel to a version that includes the fixed logic for tk_get_aux_ts64 and disable auxiliary clocks to eliminate the race window entirely.
  • Immediately disable auxiliary clocks in the kernel configuration or runtime to prevent the race condition (e.g. set aux_clock_enabled=0).
  • Continuously monitor system logs for time adjustment anomalies and unexpected precision changes indicative of the described race.

Generated by OpenCVE AI on September 21, 2026 at 03:16 UTC.

Tracking

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Advisories

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History

Sat, 12 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-367
References
Metrics threat_severity

None

cvssV3_1

{'score': 2.8, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N'}

threat_severity

Low


Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: timekeeping: Check the return value of tk_get_aux_ts64 in __do_adjtimex() If the auxiliary clock is disabled during tk_get_aux_ts64() but is enabled before tks->clock_valid is checked, then uninitialized stackdata will be used in the calculations and indirectly leaked to userspace. The same race window also exists after this change and also for the core timekeeper. But in these cases the only effect would be incorrect adjustments and this is userspace's responsibility to avoid this.
Title timekeeping: Check the return value of tk_get_aux_ts64 in __do_adjtimex()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-11T19:42:03.257Z

Reserved: 2026-08-26T14:34:25.802Z

Link: CVE-2026-80927

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:18:56.397

Modified: 2026-09-11T20:18:56.397

Link: CVE-2026-80927

cve-icon Redhat

Severity : Low

Publid Date: 2026-09-11T19:42:03Z

Links: CVE-2026-80927 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-21T03:30:08Z

Weaknesses
  • CWE-367

    Time-of-check Time-of-use (TOCTOU) Race Condition