CVE-2026-52920

Analyzed Analyzed - Analysis Complete

Strict Mode Inbound Policy Bypass in Linux Kernel

Publication date: 2026-06-24

Last updated on: 2026-07-08

Assigner: kernel.org

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-06-24

Last Modified

2026-07-08

Generated

2026-07-14

AI Q&A

2026-06-24

EPSS Evaluated

2026-07-13

NVD

CVE-2026-52920

EUVD

EUVD-2026-38723

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.1
linux	linux_kernel	From 6.2 (inc) to 6.6.141 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.91 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.33 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.0.10 (exc)
linux	linux_kernel	From 5.16 (inc) to 6.1.175 (exc)
linux	linux_kernel	From 5.11 (inc) to 5.15.209 (exc)
linux	linux_kernel	From 2.6.17 (inc) to 5.10.258 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's netfilter component, specifically in the xt_policy module responsible for strict mode inbound policy matching.

The function match_policy_in() processes security path entries in reverse order, but strict policy matching requires processing the policy information in the forward order that matches the rule layout.

The fix involves deriving the strict-match policy position based on the number of transforms already processed, ensuring that multi-element inbound rules are matched consistently and correctly.

Impact Analysis

If unpatched, this vulnerability could cause incorrect matching of inbound network policies in strict mode within the Linux kernel's netfilter system.

This may lead to inconsistent enforcement of security policies on network traffic, potentially allowing unauthorized traffic or blocking legitimate traffic due to mismatched rules.

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