CVE-2026-98993: Linux kernel · namespace: don't inherit MNT_UMOUNT in clone_mnt()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in eecc9cd0fc07dba3f7fb0b2f844b4029435a2f7b : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in eecc9cd0fc07dba3f7fb0b2f844b4029435a2f7b, e2c6d326216642011da318b9edfd5d57ebd5a56f, c26c1a91ad2881a194f7af543e0b57f0870006b2 +3
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 to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in Linux kernel version 4.1 and related commits. Users and administrators should upgrade to Linux kernel 4.1 or later to remediate this vulnerability. No additional mitigations are indicated by the vendor advisory.
Description
CVE-2026-98993 is a high-severity vulnerability in the Linux kernel related to namespace mount handling. The flaw involves the MNT_UMOUNT flag being inherited incorrectly during mount cloning, which can cause mounts to be improperly detached, leaked, or left in inconsistent states. This can lead to resource leaks, corrupted mount namespaces, and potential denial of service. The issue affects Linux kernel versions 4.0.2 through 4.1. A fix has been implemented by adding MNT_UMOUNT to internal flags so it is not copied during clone_mnt().
References
- git.kernel.org/stable/c/99698cfa34e493fc091219056aae446fe9442a96 (opens in a new tab)
- git.kernel.org/stable/c/c26c1a91ad2881a194f7af543e0b57f0870006b2 (opens in a new tab)
- git.kernel.org/stable/c/eecc9cd0fc07dba3f7fb0b2f844b4029435a2f7b (opens in a new tab)
- git.kernel.org/stable/c/5077b52e9e4d72da53c50251296b99cd416765a1 (opens in a new tab)
- git.kernel.org/stable/c/e2c6d326216642011da318b9edfd5d57ebd5a56f (opens in a new tab)