CVE-2026-46040
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.
Affected versions
Linux kernel versions
4.11
and later are affected. Fixed in
5.10.258,
5.15.209,
6.1.175,
6.6.140,
6.12.86,
6.18.27,
7.0.4,
7.1-rc1
and their respective stable series.
References
The following references provide additional information about CVE-2026-46040 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/10edf7e0ffdc7faa18e2244b17722c1b882b8273
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PatchKernel patch commithttps://git.kernel.org/stable/c/3ab58cf42c46bf2366d2f55ae5c59299d5e178b7
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PatchKernel patch commithttps://git.kernel.org/stable/c/3ad9ccea1b25435f6179b57aa891960beb7ce8f9
Frequently asked questions
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What is CVE-2026-46040?
CVE-2026-46040 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.11 onward and has been patched in 5.10.258, 5.15.209, 6.1.175 and others. CVE-2026-46040 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-46040?
Yes — CVE-2026-46040 has been patched. Fixed versions include 5.10.258, 5.15.209, 6.1.175 and others. If you are running Linux kernel 4.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-46040 actively exploited?
No — CVE-2026-46040 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.