CVE-2026-80927

Kernel stack disclosure via unchecked auxiliary timestamp

Published Sep 11, 2026 · Updated Sep 11, 2026

Uninitialized-data exposure in Linux 6.17 allows local users to indirectly read kernel stack data through clock adjustment calls. Within __do_adjtimex(), tk_get_aux_ts64() can return after the auxiliary clock is disabled, but the caller ignores that result and later calculates with an uninitialized timestamp. The race requires the auxiliary clock to be re-enabled before clock_valid is checked; when it succeeds, stack contents are indirectly exposed to userspace.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-data exposure in Linux 6.17 allows local users to indirectly read kernel stack data through clock adjustment calls. Within __do_adjtimex(), tk_get_aux_ts64() can return after the auxiliary clock is disabled, but the caller ignores that result and later calculates with an uninitialized timestamp. The race requires the auxiliary clock to be re-enabled before clock_valid is checked; when it succeeds, stack contents are indirectly exposed to userspace.

The record

CVE
CVE-2026-80927
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <4b61084b11bcecce86d03804ff30f8d7b465593c
  2. Affected versionversion=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <bc59dac50cb45a725f7a50760c7cc72a0964f722
  3. Affected versionversion=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <fecf1e37775269ad38c172b468ad4ecc3968aa63
  4. Affected versionversion=6.17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <4b61084b11bcecce86d03804ff30f8d7b465593c; version=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <bc59dac50cb45a725f7a50760c7cc72a0964f722; version=4eca49d0b621b314ac7c80f363932ec6f6c8abc8 <fecf1e37775269ad38c172b468ad4ecc3968aa63; version=6.17

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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