CVE-2025-38717: Linux kernel · net: kcm: Fix race condition in kcm_unattach()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% 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 4 Sep 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
Affected software
| Product | 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 24.04 LTSlinuxpkg:deb/ubuntu/linux@6.8.0-136.136?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@6.8.0-1060.63?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14@6.14.0-1018.18~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1062.69?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11@6.11.0-1018.18~24.04.1?arch=source&distro=nobleOther 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 that replaces the problematic flag with a safer synchronization method. Users should apply the vendor-provided patches or update to fixed kernel versions. The affected versions are explicitly listed and should be upgraded. No additional mitigation steps are indicated or required beyond applying the fix.
Description
A race condition vulnerability in the Linux kernel's KCM (Kernel Connection Multiplexor) subsystem was identified and fixed. The issue involved improper synchronization in the kcm_unattach() function, which could lead to use-after-free conditions when kcm_unattach() and kcm_release() execute concurrently. The fix replaces a problematic flag check with a more reliable synchronization method to prevent requeuing work on a freed object.
References
- ubuntu.com/security/CVE-2025-38717 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38717 (opens in a new tab)
- git.kernel.org/linus/52565a935213cd6a8662ddb8efe5b4219343a25d (opens in a new tab)
- git.kernel.org/stable/c/52565a935213cd6a8662ddb8efe5b4219343a25d (opens in a new tab)
- git.kernel.org/stable/c/7275dc3bb8f91b23125ff3f47b6529935cf46152 (opens in a new tab)
- git.kernel.org/stable/c/798733ee5d5788b12e8a52db1519abc17e826f69 (opens in a new tab)
- git.kernel.org/stable/c/c0bffbc92a1ca3960fb9cdb8e9f75a68468eb308 (opens in a new tab)