CVE-2025-37956: Linux kernel · ksmbd: prevent rename with empty string
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 6.8.0-1046.49~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% 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 +29
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 May 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@6.14.0-1011.11~24.04.1?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 included in recent Linux kernel updates. Users should update their Linux kernel to the fixed versions provided by their distribution, such as those listed in the Ubuntu security notice USN-7699-1. After updating, a system reboot is required to apply the fix. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. No additional mitigation actions are required beyond applying the official patch.
Description
A vulnerability in the Linux kernel's ksmbd server allowed clients to send an empty string as the new name during a rename operation, causing a kernel oops due to a null pointer dereference in d_alloc. This issue has been resolved by patching the kernel to return an error when an empty new name string is provided for renaming files or directories. The vulnerability affects specific Linux kernel versions and has a high CVSS score of 8.8. A patch is available and included in recent Linux kernel updates.
References
- ubuntu.com/security/CVE-2025-37956 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-37956 (opens in a new tab)
- git.kernel.org/linus/53e3e5babc0963a92d856a5ec0ce92c59f54bc12 (opens in a new tab)
- git.kernel.org/stable/c/53e3e5babc0963a92d856a5ec0ce92c59f54bc12 (opens in a new tab)
- git.kernel.org/stable/c/6ee551672c8cf36108b0cfba92ec0c7c28ac3439 (opens in a new tab)
- git.kernel.org/stable/c/c57301e332cc413fe0a7294a90725f4e21e9549d (opens in a new tab)
- git.kernel.org/stable/c/d7f2c00acb1ef64304fd40ac507e9213ff1d9b5c (opens in a new tab)
- ubuntu.com/security/notices/USN-7699-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7699-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7721-1 (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)
- 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)