CVE-2025-40341: Linux kernel · futex: Don't leak robust_list pointer on exec race
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.8.0-1050.53~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1050.53~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1052.55~22.04.1 +35
Exploitation evidence
Disclosed: evidence found.
CVE published 9 Dec 2025
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 25.10linuxpkg:deb/ubuntu/linux@6.17.0-14.14?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1007.7?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questingOther 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
An official fix is available and should be applied. The vulnerability is resolved by synchronizing access to the robust_list pointer with a read lock on exec_update_lock, preventing the race condition during exec transitions. Users should update their Linux kernel to a patched version as indicated by the vendor advisory.
Description
A race condition vulnerability in the Linux kernel futex subsystem allows a timing window during exec() where a non-privileged process transitioning to a privileged state can leak its robust_list pointer. This occurs because ptrace_may_access() checks permissions before the exec transition completes, potentially exposing sensitive memory addresses. The issue is fixed by synchronizing access with a read lock on exec_update_lock to ensure stable credentials during the check.
References
- ubuntu.com/security/CVE-2025-40341 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40341 (opens in a new tab)
- git.kernel.org/linus/6b54082c3ed4dc9821cdf0edb17302355cc5bb45 (opens in a new tab)
- git.kernel.org/stable/c/3b4222494489f6d4b8705a496dab03384b7ca998 (opens in a new tab)
- git.kernel.org/stable/c/4aced32596ead1820b7dbd8e40d30b30dc1f3ad4 (opens in a new tab)
- git.kernel.org/stable/c/6511984d1aa1360181bcafb1ca75df7f291ef237 (opens in a new tab)
- git.kernel.org/stable/c/6b54082c3ed4dc9821cdf0edb17302355cc5bb45 (opens in a new tab)
- git.kernel.org/stable/c/b524455a51feb6013df3a5dba3160487b2e8e22a (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8100-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8095-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8125-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8126-1 (opens in a new tab)