CVE-2026-98981: Linux kernel · namespace: unhash a dentry before detaching the mounts on it
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 28 Oct 2026, 01:59 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 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 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther 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 for this vulnerability has been implemented by changing the order of operations to unhash the dentry before detaching mounts, preventing lookups from accessing stale mountpoints. Users should apply the official patches or upgrade to fixed kernel versions. Since this is a kernel vulnerability, updating the Linux kernel to a patched version is the recommended mitigation. No additional vendor advisory was provided, so check the vendor or distribution security advisories for the exact fixed versions and apply updates accordingly.
Description
A vulnerability in the Linux kernel's namespace handling allows a race condition during unlink, rmdir, and rename operations on mountpoint dentries. The issue arises because the dentry is not unhashed before detaching mounts, enabling lookups to access stale mount data during the race window. This can lead to unauthorized access to files or directories that should have been hidden by mounts. The flaw affects certain Linux kernel versions and has been assigned CVE-2026-98981 with a high severity rating.
References
- ubuntu.com/security/CVE-2026-98981 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98981 (opens in a new tab)
- git.kernel.org/stable/c/528b383dc35d1e5caf64ddf5d35f983ae543b0d0 (opens in a new tab)
- git.kernel.org/stable/c/8300de4aa5d09061bfcf2af5b52c0cdba3873185 (opens in a new tab)
- git.kernel.org/stable/c/8d71bfc9b3fc15d7103e82ea9dc5057541866e46 (opens in a new tab)
- git.kernel.org/stable/c/d29cd99db3db74cf3447be74d25740981789d461 (opens in a new tab)
- git.kernel.org/stable/c/db90eecbde319527aa9480c039d32a0f5fe80574 (opens in a new tab)