CVE-2026-23319: Linux kernel · bpf: Fix a UAF issue in bpf_trampoline_link_cgroup_shim
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in cfcfa0ca0212162aa472551266038e8fd6768cff : patch Linux kernel soon.
Data as of 10 Nov 2026, 13:02 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- Patch
- Available – fixed in cfcfa0ca0212162aa472551266038e8fd6768cff, 56145d237385ca0e7ca9ff7b226aaf2eb8ef368b, 529e685e522b9d7fb379dbe6929dcdf520e34c8c +3
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 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 10 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
AI-suggested
A patch has been implemented and is available in the Linux kernel source. Users and administrators should update to the fixed kernel versions containing the patch to remediate this vulnerability. No additional mitigation steps are necessary once the patch is applied.
Description
A use-after-free (UAF) vulnerability was identified and fixed in the Linux kernel's BPF subsystem, specifically in the bpf_trampoline_link_cgroup_shim function. The flaw occurs due to a race condition where a resource's reference count reaches zero and is considered released, but it may still be referenced elsewhere before actual cleanup. This window allows another process to trigger a use-after-free condition. The fix involves adding an atomic check to ensure the reference count is only incremented if it is non-zero, preventing the UAF scenario.
References
- git.kernel.org/stable/c/529e685e522b9d7fb379dbe6929dcdf520e34c8c (opens in a new tab)
- git.kernel.org/stable/c/9b02c5c4147f8af8ed783c8deb5df927a55c3951 (opens in a new tab)
- git.kernel.org/stable/c/cfcfa0ca0212162aa472551266038e8fd6768cff (opens in a new tab)
- git.kernel.org/stable/c/3eeddb80191f7626ec1ef742bfff51ec3b0fa5c2 (opens in a new tab)
- git.kernel.org/stable/c/4e8a0005d633a4adc98e3b65d5080f93b90d356b (opens in a new tab)
- git.kernel.org/stable/c/56145d237385ca0e7ca9ff7b226aaf2eb8ef368b (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-082556.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)