VulnerabilityPublished 28 Oct 2026

CVE-2026-99129: Linux kernel · selinux: fix BPF token permission checks

Source GCVE Database

Authoritative record:CVE-2026-99129

Not known to be exploited : upgrade to e1ef306ba20eb13099ca4463527890df67619405 or 77d499e61d36e883a6ad1f10afe05f556aa7e0cc when convenient.

Data as of 28 Oct 2026, 14:02 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Patch: Available – fixed in e1ef306ba20eb13099ca4463527890df67619405, 77d499e61d36e883a6ad1f10afe05f556aa7e0cc

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-x4j5-868q-98xc

What to do

Upgrade Linux kernel to e1ef306ba20eb13099ca4463527890df67619405 or 77d499e61d36e883a6ad1f10afe05f556aa7e0cc.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 5473a722f782f79f96b4691400d681c01fcacc2f, < e1ef306ba20eb13099ca4463527890df67619405	Fixed in e1ef306ba20eb13099ca4463527890df67619405
LinuxLinux	Affected ≥ 5473a722f782f79f96b4691400d681c01fcacc2f, < 77d499e61d36e883a6ad1f10afe05f556aa7e0cc	Fixed in 77d499e61d36e883a6ad1f10afe05f556aa7e0cc
LinuxLinux	Affected =7.0	Fixed in–

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel. Users and administrators should apply the official kernel updates that include this patch to ensure the vulnerability is remediated.

Description

A vulnerability in the Linux kernel's SELinux implementation related to BPF token permission checks has been fixed. The issue involved multiple lookups of the bpffs creator SID using the token's file descriptor, which could lead to potential time-of-check to time-of-use (TOCTOU) race conditions if the token file descriptor was changed by the user. The fix simplifies the code by using the resolved path/dentry or the token itself to obtain the necessary information, thereby avoiding these TOCTOU issues.

Impact

This vulnerability could allow an attacker to exploit a time-of-check to time-of-use (TOCTOU) race condition by changing the token file descriptor between permission checks, potentially bypassing SELinux BPF token permission enforcement. However, no known exploits in the wild have been reported.

Summary

CVE-2026-99129 addresses a vulnerability in the Linux kernel's SELinux subsystem concerning BPF token permission checks. The flaw involved redundant lookups of the bpffs creator security identifier (SID) via the token's file descriptor, which could be manipulated by a user to cause TOCTOU race conditions. The patch modifies the code to retrieve the creator SID from the resolved path/dentry or directly from the token, eliminating the multiple lookups and mitigating the race condition risk.

References

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