CVE-2025-68788: Linux kernel · fsnotify: do not generate ACCESS/MODIFY events on child for special files
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1103.110~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1103.110~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1114.123~20.04.1 +71
Exploitation evidence
Disclosed: evidence found.
CVE published 13 Jan 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 |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-22.22?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1012.12?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1013.13?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1012.12?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1011.11?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and has been released to correct this behavior in the Linux kernel. Users should update to a fixed kernel version as provided by their distribution vendor. The Ubuntu advisory USN-8096-1 confirms the availability of this fix in updated kernel packages. Applying these updates will close the side-channel vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's fsnotify subsystem allowed users with read access to a parent directory but no read access to special files (e.g., /dev/null) to receive ACCESS/MODIFY events on those special files. This behavior could leak information about file access or modification times, creating a side-channel for potential information exfiltration. The issue has been resolved by aligning fsnotify events with file stat behavior, preventing ACCESS/MODIFY events on special files for unauthorized users. This fix closes the side-channel without affecting legitimate event notifications triggered by explicit time attribute changes.
References
- ubuntu.com/security/CVE-2025-68788 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68788 (opens in a new tab)
- git.kernel.org/linus/635bc4def026a24e071436f4f356ea08c0eed6ff (opens in a new tab)
- git.kernel.org/stable/c/635bc4def026a24e071436f4f356ea08c0eed6ff (opens in a new tab)
- git.kernel.org/stable/c/6a7d7d96eeeab7af2bd01afbb3d9878a11a13d91 (opens in a new tab)
- git.kernel.org/stable/c/7a93edb23bcf07a3aaf8b598edfc2faa8fbcc0b6 (opens in a new tab)
- git.kernel.org/stable/c/82f7416bcbd951549e758d15fc1a96a5afc2e900 (opens in a new tab)
- git.kernel.org/stable/c/e0643d46759db8b84c0504a676043e5e341b6c81 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8116-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8141-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8179-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8177-2 (opens in a new tab)