Local activity disclosure via special-file fsnotify events
Published Jan 13, 2026 · Updated Jan 13, 2026
Information disclosure in Linux kernel fsnotify allows local users to infer special-file activity through parent-directory watches. The fsnotify path emits FS_ACCESS and FS_MODIFY events for special-file children to inotify or fanotify watchers on an accessible parent, even when the watcher cannot read the child. Access to the parent directory, such as /dev, is sufficient to observe another user's reads or writes as a timing side channel without reading the special file itself.
Summary
What happened
Information disclosure in Linux kernel fsnotify allows local users to infer special-file activity through parent-directory watches. The fsnotify path emits FS_ACCESS and FS_MODIFY events for special-file children to inotify or fanotify watchers on an accessible parent, even when the watcher cannot read the child. Access to the parent directory, such as /dev, is sufficient to observe another user's reads or writes as a timing side channel without reading the special file itself.
The record
- CVE
- CVE-2025-68788
- Published
- Jan 13, 2026
- Updated
- Jan 13, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 13, 2026CVE publishedPublication date reported by the CVE source.
- Jan 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <635bc4def026a24e071436f4f356ea08c0eed6ff
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6a7d7d96eeeab7af2bd01afbb3d9878a11a13d91
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7a93edb23bcf07a3aaf8b598edfc2faa8fbcc0b6
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <82f7416bcbd951549e758d15fc1a96a5afc2e900
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e0643d46759db8b84c0504a676043e5e341b6c81
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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