CVE-2026-93813: Linux kernel · btrfs: tree-checker: validate INODE_REF's namelen
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 2026
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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 adds proper validation of the INODE_REF namelen to prevent out-of-bound memory access. Systems should apply the official Linux kernel updates that include this patch. Until patched, avoid mounting or processing untrusted Btrfs images that could trigger this vulnerability.
Description
A vulnerability in the Linux kernel's Btrfs filesystem tree-checker component allows a crafted Btrfs image with an invalid INODE_REF name length to cause a kernel crash. The issue arises because the namelen field can be set to 4096, exceeding the normal limit of 255, leading to out-of-bound memory access and a kernel panic. This vulnerability has been resolved by adding extra validation for the INODE_REF namelen, rejecting crafted images with invalid lengths.
References
- ubuntu.com/security/CVE-2026-93813 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-93813 (opens in a new tab)
- git.kernel.org/stable/c/eeddee090b834a7d4b6a8214d2e3739e64c7a338 (opens in a new tab)
- git.kernel.org/stable/c/8f75c19892263bc0555fba922aefe103e841e86d (opens in a new tab)
- git.kernel.org/stable/c/3dc22abc21f5892406c09202fa2627196cc96967 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-93813 (opens in a new tab)
- git.kernel.org/stable/c/4cb41f07685f88ec724a375883bb0c731db8f6eb (opens in a new tab)
- git.kernel.org/stable/c/509d6a4d889e425f305461d8323a7b39ca6c121c (opens in a new tab)
- git.kernel.org/stable/c/60078a3e25c09d9d8fba828b0d81bb33e449a1b2 (opens in a new tab)