CVE-2026-74658: Linux kernel · futex: Prevent robust futex exit race some more
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +26
Exploitation evidence
Disclosed: evidence found.
CVE published 22 Aug 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions. The vendor advisory confirms that this issue has been fixed. No additional mitigation actions are required beyond applying the official kernel updates.
Description
A vulnerability in the Linux kernel's futex implementation could cause waiters on a robust futex to sleep indefinitely due to a race condition in the robust futex exit processing. This occurs when a woken waiter is killed before it can re-arm the FUTEX_WAITERS bit, leading to lost wake notifications and potential deadlocks. The issue has been addressed by augmenting the robust list exit processing to perform an extra wakeup in certain conditions. This fix does not fully resolve all related futex contention issues but mitigates the described race condition.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74658 (opens in a new tab)
- git.kernel.org/stable/c/33bfa85458105d6169ebdb697f692b8bb8025bae (opens in a new tab)
- git.kernel.org/stable/c/6d4514ca9cdf61fec4ec634cf50386f6f7e69748 (opens in a new tab)
- git.kernel.org/stable/c/7b8c53263f8878bdd12c87e147ac6feca5c05211 (opens in a new tab)
- git.kernel.org/stable/c/7cf710e70f9bb8ea75f759ebed09871801315992 (opens in a new tab)
- git.kernel.org/stable/c/83b0f71d5a313a765754acab51d2ecc5de76e0b9 (opens in a new tab)
- git.kernel.org/stable/c/925628656b73b70930972ccde421de4f758d8650 (opens in a new tab)
- git.kernel.org/stable/c/a1c2b7b86a946b6b172bce44d74553da2323a36c (opens in a new tab)
- git.kernel.org/stable/c/aa5c571901c6b22b58373693a4bf889ecab11ff5 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74658 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74658 (opens in a new tab)
- git.kernel.org/linus/6d4514ca9cdf61fec4ec634cf50386f6f7e69748 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)