CVE-2025-38561: Linux kernel · ksmbd: fix Preauh_HashValue race condition
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1099.106~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1099.106~20.04.1, 5.15.0-1103.112~20.04.1, 5.15.0-1099.108~20.04.1 +61
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Aug 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.
Patches and advisories
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8016-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?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.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix Preauh_HashValue race condition If client send multiple session setup requests to ksmbd, Preauh_HashValue race condition could happen. There is no need to free sess->Preauh_HashValue at session setup phase. It can be freed together with session at connection termination phase.
References
- ubuntu.com/security/CVE-2025-38561 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38561 (opens in a new tab)
- git.kernel.org/linus/44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6 (opens in a new tab)
- git.kernel.org/stable/c/44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6 (opens in a new tab)
- git.kernel.org/stable/c/6613887da1d18dd2ecfd6c6148a873c4d903ebdc (opens in a new tab)
- git.kernel.org/stable/c/7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fc (opens in a new tab)
- git.kernel.org/stable/c/b69fd87076daa66f3d186bd421a7b0ee0cb45829 (opens in a new tab)
- git.kernel.org/stable/c/edeecc7871e8fc0878d53ce286c75040a0e38f6c (opens in a new tab)
- git.kernel.org/stable/c/fbf5c0845ed15122a770bca9be1d9b60b470d3aa (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7880-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7879-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7934-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8013-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8015-2 (opens in a new tab)