CVE-2026-53212
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_tunnel: fix use-after-free on object destroy nft_tunnel_obj_destroy() calls metadata_dst_free() which directly kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets that took a reference via dst_hold() in nft_tunnel_obj_eval() and are still queued (e.g. in a netem qdisc) are left with a dangling pointer. When these packets are eventually dequeued, dst_release() operates on freed memory. Replace metadata_dst_free() with dst_release() so the metadata_dst is freed only after all references are dropped. The dst subsystem already handles metadata_dst cleanup in dst_destroy() when DST_METADATA is set.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 6.12.94-1 |
| sid | Fixed | 7.0.13-1 |
| forky | Affected | โ |
| bullseye | Affected | โ |
| bookworm | Affected | โ |
References
- https://git.kernel.org/stable/c/349df61526d2e39decc685d246202e3e284cfe05
- https://git.kernel.org/stable/c/55b79b1ae42372012413ce0413181d26679b17ef
- https://git.kernel.org/stable/c/5e9ee18b27fde88cb6148202b33916c66693fe82
- https://git.kernel.org/stable/c/8767fe4079affa74314d7eb3220e700150289842
- https://git.kernel.org/stable/c/fda6573a46ad24f35348e024905ee5bdf729797e
- https://git.kernel.org/stable/c/941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3
- https://git.kernel.org/stable/c/f9a0e4b61054cde89a2a77845293c726cc07cc43
- https://git.kernel.org/stable/c/c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a
- https://security-tracker.debian.org/tracker/CVE-2026-53212
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.