CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
4Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: release flowtable after rcu grace period on error Call synchronize_rcu() after unregistering the hooks from error path, since a hook that already refers to this flowtable can be already registered, exposing this flowtable to packet path and nfnetlink_hook control plane. This error path is rare, it should only happen by reaching the maximum number hooks or by failing to set up to hardware offload, just call synchronize_rcu(). There is a check for already used device hooks by different flowtable that could result in EEXIST at this late stage. The hook parser can be updated to perform this check earlier to this error path really becomes rarely exercised. Uncovered by KASAN reported as use-after-free from nfnetlink_hook path when dumping hooks.
Analysis
A use-after-free vulnerability exists in the Linux kernel's netfilter nf_tables flowtable implementation during error handling in the hook registration path. When hook registration fails (due to reaching maximum hook limits or hardware offload setup failures), the flowtable is not properly synchronized with RCU grace periods before being released, allowing concurrent packet processing or control plane operations (nfnetlink_hook) to access freed memory. …
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Priority Score
Vendor Status
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| bullseye | vulnerable | 5.10.223-1 | - |
| bullseye (security) | vulnerable | 5.10.251-1 | - |
| bookworm | vulnerable | 6.1.159-1 | - |
| bookworm (security) | vulnerable | 6.1.164-1 | - |
| trixie | vulnerable | 6.12.73-1 | - |
| trixie (security) | vulnerable | 6.12.74-2 | - |
| forky, sid | vulnerable | 6.19.8-1 | - |
| (unstable) | fixed | (unfixed) | - |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-15393
GHSA-f5vj-m443-mgw6