CVE-2026-72404: Linux kernel · tipc: fix UAF in cleanup_bearer() due to premature dst_cache_destroy()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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
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 fix is available that defers cache destruction and memory freeing until after all concurrent readers have completed, using RCU callbacks and synchronization primitives. Users should apply the official kernel updates that include this fix. No additional mitigation steps are indicated beyond applying the patch.
Description
A use-after-free (UAF) vulnerability in the Linux kernel's TIPC UDP media bearer cleanup function (cleanup_bearer) was fixed. The issue arises because dst_cache_destroy() is called prematurely, freeing per-CPU cache memory without proper synchronization, which can lead to crashes or warnings when concurrent transmitters access freed memory. The fix defers destruction of cache entries and memory freeing until after ensuring no concurrent readers remain, using RCU callbacks and proper synchronization.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72404 (opens in a new tab)
- git.kernel.org/stable/c/1c8393eefa3cadf4ca0b61119ad1321aa32d3c8c (opens in a new tab)
- git.kernel.org/stable/c/7116764ca53ff529335d7ab7c364a69f094b23a5 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72404 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72404 (opens in a new tab)
- git.kernel.org/linus/7116764ca53ff529335d7ab7c364a69f094b23a5 (opens in a new tab)
- git.kernel.org/stable/c/3827ff67f9fbecd1086e33d23693ef6a1a9c6c38 (opens in a new tab)
- git.kernel.org/stable/c/6aeb4ba4fb098199e13723cfd04d9a749741f731 (opens in a new tab)
- git.kernel.org/stable/c/6b0e29f7662c237e717f35dad746efe94715d0da (opens in a new tab)