VulnerabilityPublished 23 Oct 2026

CVE-2026-98977: Linux kernel · namespace: handle mount locking for automounts correctly

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in e01c79761c7b3373e80094c5eadb21cb864fa8bc : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in e01c79761c7b3373e80094c5eadb21cb864fa8bc, b3ccde78f1608836e62320428abc0e8aa9cf2329, 33aadc7c72055fca93cb5a3691d836ebf8b31c9b +3

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=3.8.6 <3.9	Fixed in e01c79761c7b3373e80094c5eadb21cb864fa8bc b3ccde78f1608836e62320428abc0e8aa9cf2329 33aadc7c72055fca93cb5a3691d836ebf8b31c9b 6ab37fae14196ba2262b152a7d9222c50356d278 5e8f3ac8fa3d411b422ad32b9168c46a4824cc79 3.9
LinuxLinux	Affected =3.9	Fixed in–

AI-suggested

A fix for this vulnerability is available and included in Linux kernel version 3.9. Users and administrators should upgrade to version 3.9 or later to remediate this issue. No additional mitigation steps are indicated beyond applying the official fix.

Description

CVE-2026-98977 is a vulnerability in the Linux kernel related to incorrect handling of mount locking for automounts when mounts are propagated across user namespaces. The issue arises because the locking mechanism incorrectly locks the host's mount instead of the child's copy in the user namespace, potentially preventing the host from changing mount flags. This flaw was fixed in Linux kernel version 3.9 and later.

Impact

The vulnerability can cause the host's mount to be locked incorrectly, preventing changes to mount flags such as remount operations. This could lead to permission errors (EPERM) on the host side while allowing the child namespace to perform the operation successfully. Although the impact is primarily on mount flag management and namespace isolation, it may affect system stability or security policies relying on mount flags.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:54 UTC

Technical details

References

Community reviews

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