CVE-2026-98991: Linux kernel · namespace: queue a mount only once for mount notifications
Source GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in bd2feb7796b6585938a4241e7b7c4148a6f7b762 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in bd2feb7796b6585938a4241e7b7c4148a6f7b762, acbe9e4418e2ef7bef1a12e62e0e7d6145a15190, 702ff3fe499876e09c45558a05366d21a5bc41ab
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 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
Upgrade Linux kernel to bd2feb7796b6585938a4241e7b7c4148a6f7b762, acbe9e4418e2ef7bef1a12e62e0e7d6145a15190 or 702ff3fe499876e09c45558a05366d21a5bc41ab.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix has been implemented in the Linux kernel to initialize the notification list properly and prevent mounts from being queued multiple times. Users should apply the official kernel update that includes this fix once available. Since this is a kernel-level issue, upgrading to the patched kernel version is the recommended mitigation. No other specific workarounds are indicated.
Description
A vulnerability in the Linux kernel's mount notification system allows a mount to be queued multiple times for notifications, leading to use-after-free memory access. This occurs because mnt_notify_add() does not check if a mount is already on the notification list, causing corrupted list state and potential kernel memory errors. The issue affects mounts with the MNT_SHRINKABLE flag, such as submounts of NFS, AFS, CIFS, and tracefs. The flaw has been resolved by initializing the notification list properly and preventing duplicate queueing of mounts.
References
- nvd.nist.gov/vuln/detail/CVE-2026-98991 (opens in a new tab)
- git.kernel.org/stable/c/702ff3fe499876e09c45558a05366d21a5bc41ab (opens in a new tab)
- git.kernel.org/stable/c/acbe9e4418e2ef7bef1a12e62e0e7d6145a15190 (opens in a new tab)
- git.kernel.org/stable/c/bd2feb7796b6585938a4241e7b7c4148a6f7b762 (opens in a new tab)