CVE-2026-74363: Linux kernel · bpf: fix UAF by restoring RCU-delayed inode freeing in bpffs
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 should be applied to affected Linux kernel versions. The fix properly restores RCU-delayed inode freeing to prevent use-after-free conditions. Users should update to patched kernel versions as provided by their Linux distribution vendors. No additional mitigation is required beyond applying the official fix.
Description
A use-after-free vulnerability in the Linux kernel's BPF filesystem (bpffs) was fixed by restoring RCU-delayed inode freeing. The issue arose because inode cleanup was moved from free_inode() to destroy_inode(), removing the RCU delay and causing a use-after-free when concurrent unlink operations occurred. This could lead to kernel memory corruption and potentially allow local attackers to compromise system integrity. The vulnerability affects specific Linux kernel versions and has a high severity score. A patch is available to properly separate blocking cleanup and RCU-delayed freeing, preventing the use-after-free condition.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74363 (opens in a new tab)
- git.kernel.org/stable/c/0497ff765746d9b2d17445c8f7cc737b36c0152a (opens in a new tab)
- git.kernel.org/stable/c/53649846e0437d1d9b7cb993cfe54c367addf7ae (opens in a new tab)
- git.kernel.org/stable/c/5fecb71c10c28aef276ba49c718dc961745fdcf0 (opens in a new tab)
- git.kernel.org/stable/c/61f19729728243c82476dee31315143ed3275e7f (opens in a new tab)
- git.kernel.org/stable/c/b93c55b4932dd7e32dca8cf34a3443cc87a02906 (opens in a new tab)
- git.kernel.org/stable/c/c70d0f9114c3cc156f6029a400c4eb7e6f7c82b2 (opens in a new tab)
- git.kernel.org/stable/c/ea1c243c39e32b7fc1c2edfe32081ff7e30a877c (opens in a new tab)
- ubuntu.com/security/CVE-2026-74363 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74363 (opens in a new tab)
- git.kernel.org/linus/b93c55b4932dd7e32dca8cf34a3443cc87a02906 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)