CVE-2026-53220
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: revalidate bridge ports ebt_redirect_tg() dereferences br_port_get_rcu() return without a NULL check, causing a kernel panic when the bridge port has been removed between the original hook invocation and an NFQUEUE reinject. A mere NULL check isn't sufficient, however. As sashiko review points out userspace can not only remove the port from the bridge, it could also place the device in a different virtual device, e.g. macvlan. If this happens, we must drop the packet, there is no way for us to reinject it into the bridge path. Switch to _upper API, we don't need the bridge port structure. Also, this fix keeps another bug intact: Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER too aggressive, which prevents certain logging features when queueing in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old CONFIG_BRIDGE_NETFILTER cruft is off. Fixes tag is a common ancestor, this was always broken.
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 — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → 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 | — |
| bullseye | Affected | — |
| bookworm | Affected | — |
References
- https://git.kernel.org/stable/c/43330a1e8aace6b5a8de9aba127e9e394ab49b0f
- https://git.kernel.org/stable/c/4beffcd726e2a731cea4dc18e1fbc55c8d76f1a0
- https://git.kernel.org/stable/c/d4b1301fd3c9e5e105fd3767c68bc4ba558bb228
- https://git.kernel.org/stable/c/ccb9fd4b87538ccf19ccff78ee26700526d94867
- https://security-tracker.debian.org/tracker/CVE-2026-53220
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.