CVE-2025-40201: Linux kernel · kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64()
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 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
AI-suggested
A fix has been implemented in the Linux kernel by modifying sys_prlimit64() to take the tasklist_lock when necessary to prevent race conditions. Users and administrators should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended mitigation. Patch status is not explicitly confirmed in the provided data; check the vendor or Linux kernel stable release notes for the exact fixed versions and apply updates accordingly.
Description
A race condition vulnerability in the Linux kernel's sys_prlimit64() function involving improper locking of task group leaders has been resolved. The issue arises from unsafe usage of task_lock(tsk->group_leader), which can lead to accessing freed task_struct objects or taking incorrect locks due to concurrent changes in group_leader. This can cause serious kernel-level integrity and availability issues.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40201 (opens in a new tab)
- git.kernel.org/stable/c/132f827e7bac7373e1522e89709d70b43cae5342 (opens in a new tab)
- git.kernel.org/stable/c/19b45c84bd9fd42fa97ff80c6350d604cb871c75 (opens in a new tab)
- git.kernel.org/stable/c/1bc0d9315ef5296abb2c9fd840336255850ded18 (opens in a new tab)
- git.kernel.org/stable/c/6796412decd2d8de8ec708213bbc958fab72f143 (opens in a new tab)
- git.kernel.org/stable/c/a15f37a40145c986cdf289a4b88390f35efdecc4 (opens in a new tab)