CVE-2026-98991: Linux kernel · namespace: queue a mount only once for mount notifications
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in bd2feb7796b6585938a4241e7b7c4148a6f7b762 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:07 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
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific Linux kernel commits identified by their hashes. Users and administrators should update affected Linux kernel installations from version 6.15 to a fixed version containing these commits. No additional mitigation is required once patched.
Description
CVE-2026-98991 is a high-severity vulnerability in the Linux kernel related to mount notification handling. The flaw occurs because the kernel does not prevent a mount from being queued multiple times for notifications, leading to a use-after-free condition. This can cause kernel memory corruption and crashes when mount operations access freed memory. The issue affects Linux kernel version 6.15 and has been fixed in subsequent commits.