CVE-2025-38728: Linux kernel · smb3: fix for slab out of bounds on mount to ksmbd
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.1 Critical · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1046.49~22.04.1, 6.8.0-1051.57~22.04.1, 6.8.0-1047.50~22.04.2 +24
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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
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@6.14.0-1018.18~24.04.1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1046.52?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 remediate this vulnerability. The Ubuntu security advisory USN-8028-1 confirms that fixes have been released. Users should update their Linux kernel to a patched version as soon as possible to mitigate this issue.
Description
A vulnerability in the Linux kernel's SMB3 implementation (ksmbd) allowed a slab out-of-bounds read during mount operations when KASAN was enabled, due to a missing check in parse_server_interfaces(). This issue was resolved in a Linux kernel update. The vulnerability has a high CVSS score of 9.1, indicating critical impact on confidentiality and availability. Multiple specific Linux kernel versions are affected. A patch is available to fix this issue.
References
- ubuntu.com/security/CVE-2025-38728 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38728 (opens in a new tab)
- git.kernel.org/linus/7d34ec36abb84fdfb6632a0f2cbda90379ae21fc (opens in a new tab)
- git.kernel.org/stable/c/7d34ec36abb84fdfb6632a0f2cbda90379ae21fc (opens in a new tab)
- git.kernel.org/stable/c/8de33d4d72e8fae3502ec3850bd7b14e7c7328b6 (opens in a new tab)
- git.kernel.org/stable/c/9bdb8e98a0073c73ab3e6c631ec78877ceb64565 (opens in a new tab)
- git.kernel.org/stable/c/a0620e1525663edd8c4594f49fb75fe5be4724b0 (opens in a new tab)
- git.kernel.org/stable/c/a542f93a123555d09c3ce8bc947f7b56ad8e6463 (opens in a new tab)
- git.kernel.org/stable/c/f6eda5b0e8f8123564c5b34f5801d63243032eac (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)
- ubuntu.com/security/notices/USN-8028-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-6 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8052-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-7 (opens in a new tab)