VulnerabilityPublished 27 May 2026Updated 6 Nov 2026

CVE-2026-46040: Linux kernel · inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in fdaa42ca370d056428e5e171247c8fdce8dff36a : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:34 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in fdaa42ca370d056428e5e171247c8fdce8dff36a, 73ddc8518a32baff6bc17afda4ee1ebae5b4ed12, 10edf7e0ffdc7faa18e2244b17722c1b882b8273 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < fdaa42ca370d056428e5e171247c8fdce8dff36a	Fixed in fdaa42ca370d056428e5e171247c8fdce8dff36a
LinuxLinux	Affected ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < 73ddc8518a32baff6bc17afda4ee1ebae5b4ed12	Fixed in 73ddc8518a32baff6bc17afda4ee1ebae5b4ed12
LinuxLinux	Affected ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < 10edf7e0ffdc7faa18e2244b17722c1b882b8273	Fixed in 10edf7e0ffdc7faa18e2244b17722c1b882b8273
LinuxLinux	Affected ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < 9e48844f708eb48bae4e79cb21edc097c966306d	Fixed in 9e48844f708eb48bae4e79cb21edc097c966306d
LinuxLinux	Affected ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < 8bcc1cd237ab5ccfdd102869fa031c541943cf40	Fixed in 8bcc1cd237ab5ccfdd102869fa031c541943cf40
LinuxLinux	Affected ≥ 1cce1eea0aff51201753fcaca421df825b0813b6, < 6a320935fa4293e9e599ec9f85dc9eb3be7029f8	Fixed in 6a320935fa4293e9e599ec9f85dc9eb3be7029f8

Description

In the Linux kernel, the following vulnerability has been resolved: inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails When fsnotify_add_inode_mark_locked() fails in inotify_new_watch(), the error path calls inotify_remove_from_idr() but does not call dec_inotify_watches() to undo the preceding inc_inotify_watches(). This leaks a watch count, and repeated failures can exhaust the max_user_watches limit with -ENOSPC even when no watches are active. Prior to commit 1cce1eea0aff ("inotify: Convert to using per-namespace limits"), the watch count was incremented after fsnotify_add_mark_locked() succeeded, so this path was not affected. The conversion moved inc_inotify_watches() before the mark insertion without adding the corresponding rollback. Add the missing dec_inotify_watches() call in the error path.

References

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