CVE-2025-38562: Linux kernel · ksmbd: fix null pointer dereference error in generate_encryptionkey
Affects Linux kernelSource GCVE Database
Not known to be exploited · 11% EPSS · CVSS 5.5 Medium · fixed in 5.15.0-186.196~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 11:42 UTC
- EPSS
- 11.8% chance of exploitation in 30 days – higher than 96% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-186.196~20.04.1, 5.15.0-184.194~20.04.1, 5.15.0-1064.66~20.04.1 +43
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.
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@6.8.0-100.100?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@6.8.0-1046.49?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14@6.14.0-1017.17~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1046.52?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
A patch is available and should be applied to affected Linux kernel versions to resolve this vulnerability. The vendor advisory confirms the issue has been fixed. Users should update their Linux kernel to a version later than the affected ones listed. No additional mitigation is indicated by the vendor advisory.
Description
A null pointer dereference vulnerability in the Linux kernel's ksmbd component was fixed. The issue occurs when a client sends two session setups with Kerberos 5 authentication, potentially causing a null pointer dereference in the generate_encryptionkey function. The patch prevents this by skipping encryption key generation if the session is already valid. This vulnerability affects certain Linux kernel versions and has a medium severity rating with a CVSS score of 5.5. A patch is available to address the issue.
References
- ubuntu.com/security/CVE-2025-38562 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38562 (opens in a new tab)
- git.kernel.org/linus/9b493ab6f35178afd8d619800df9071992f715de (opens in a new tab)
- git.kernel.org/stable/c/015ef163d65496ae3ba6192c96140a22743f0353 (opens in a new tab)
- git.kernel.org/stable/c/2a30ed6428ce83afedca1a6c5c5c4247bcf12d0e (opens in a new tab)
- git.kernel.org/stable/c/96a82e19434a2522525baab59c33332658bc7653 (opens in a new tab)
- git.kernel.org/stable/c/9b493ab6f35178afd8d619800df9071992f715de (opens in a new tab)
- git.kernel.org/stable/c/9c2dbbc959e1fcc6f603a1a843e9cf743ba383bb (opens in a new tab)
- git.kernel.org/stable/c/d79c8bebaa622ee223128be7c66d8aaeeb634a57 (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-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-4 (opens in a new tab)