CVE-2026-74315: Linux kernel · lockd: Avoid hashing uninitialized bytes in nlm4svc_lookup_file()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 12 Nov 2026, 20:17 UTC
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 15 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Affected software
| Product | 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-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?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– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?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 fix is available that zeroes the uninitialized tail bytes in the file handle before hashing, ensuring consistent hashing behavior. Users should update to fixed Linux kernel versions that include this patch. The affected versions are explicitly listed and should be upgraded to versions beyond these. No alternative mitigations are indicated.
Description
A critical vulnerability in the Linux kernel's lockd component was fixed to prevent hashing uninitialized bytes in the nlm4svc_lookup_file() function. The issue caused inconsistent hashing of file handles shorter than LOCKD_FH_HASH_SIZE, leading to failed lock-state lookups. This was due to leftover data in uninitialized bytes being hashed, causing the same file handle to hash differently across calls.
References
- ubuntu.com/security/CVE-2026-74315 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74315 (opens in a new tab)
- git.kernel.org/linus/6e4c62caecf792e8a15ad9bc7f371e57c17e3302 (opens in a new tab)
- git.kernel.org/stable/c/686c2434f9f16b87aeed18d76cc562df9f2695ab (opens in a new tab)
- git.kernel.org/stable/c/6e4c62caecf792e8a15ad9bc7f371e57c17e3302 (opens in a new tab)