1. Home
  2. Vulnerabilities
  3. CVE-2026-53269
5.5
MEDIUM CVSS 3.1
CVE-2026-53269
netfilter: synproxy: add mutex to guard hook reference counting
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: add mutex to guard hook reference counting As the synproxy infrastructure register netfilter hooks on-demand when a user adds the first iptables target or nftables expression, if done concurrently they can race each other. Introduce a mutex to serialize the refcount control blocks access from both frontends. While a per namespace mutex might be more efficient, it is not needed for target/expression like SYNPROXY.

Details
INFO

Published Date :

June 25, 2026, 9:16 a.m.

Last Modified :

July 8, 2026, 4:01 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-53269 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Apply kernel updates to resolve race condition in netfilter synproxy hook reference counting.
  • Update the Linux kernel to the latest stable version.
  • Ensure all system components are patched.
  • Reboot the system after updates.
  • Verify the kernel version.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-53269.

URL Resource
https://git.kernel.org/stable/c/0ec9ddc1bda261a2c57636c74c8b4e53000102c9 Patch
https://git.kernel.org/stable/c/0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88 Patch
https://git.kernel.org/stable/c/2fcba19caaeb2a33017459d3430f057967bb91b6 Patch
https://git.kernel.org/stable/c/56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389 Patch
https://git.kernel.org/stable/c/640441348258220e78daed40528b85b8afcedab6 Patch
https://git.kernel.org/stable/c/aaf80701dc2f7a48fe543961e21f8ca3924d587c Patch
https://git.kernel.org/stable/c/debc57b83d5b323df74bf010c8d50fe26ad2ed6b Patch
https://git.kernel.org/stable/c/fbf0591275f50eae5733c3d7a8cd6c1e79933ffa Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53269 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-53269 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53269 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-53269 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jul. 08, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.143 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.3 up to (excluding) 5.10.259
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/0ec9ddc1bda261a2c57636c74c8b4e53000102c9 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/2fcba19caaeb2a33017459d3430f057967bb91b6 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/640441348258220e78daed40528b85b8afcedab6 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/aaf80701dc2f7a48fe543961e21f8ca3924d587c Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/debc57b83d5b323df74bf010c8d50fe26ad2ed6b Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/fbf0591275f50eae5733c3d7a8cd6c1e79933ffa Types: Patch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 25, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': '0ec9ddc1bda261a2c57636c74c8b4e53000102c9', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': '56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': 'debc57b83d5b323df74bf010c8d50fe26ad2ed6b', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': '0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': '640441348258220e78daed40528b85b8afcedab6', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': 'aaf80701dc2f7a48fe543961e21f8ca3924d587c', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': 'fbf0591275f50eae5733c3d7a8cd6c1e79933ffa', 'versionType': 'git'}, {'status': 'affected', 'version': 'ad49d86e07a497e834cb06f2b151dccd75f8e148', 'lessThan': '2fcba19caaeb2a33017459d3430f057967bb91b6', 'versionType': 'git'}], 'programFiles': ['net/netfilter/nf_synproxy_core.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.3'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.3', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.94', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.36', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.13', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/netfilter/nf_synproxy_core.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: add mutex to guard hook reference counting As the synproxy infrastructure register netfilter hooks on-demand when a user adds the first iptables target or nftables expression, if done concurrently they can race each other. Introduce a mutex to serialize the refcount control blocks access from both frontends. While a per namespace mutex might be more efficient, it is not needed for target/expression like SYNPROXY.
    Added Reference https://git.kernel.org/stable/c/0ec9ddc1bda261a2c57636c74c8b4e53000102c9
    Added Reference https://git.kernel.org/stable/c/0f8ba5e4c53d2e4a536aa68140beda9fe59b2f88
    Added Reference https://git.kernel.org/stable/c/2fcba19caaeb2a33017459d3430f057967bb91b6
    Added Reference https://git.kernel.org/stable/c/56ffbe3a08c01dcdb0d6adee9ce1e535bfb3b389
    Added Reference https://git.kernel.org/stable/c/640441348258220e78daed40528b85b8afcedab6
    Added Reference https://git.kernel.org/stable/c/aaf80701dc2f7a48fe543961e21f8ca3924d587c
    Added Reference https://git.kernel.org/stable/c/debc57b83d5b323df74bf010c8d50fe26ad2ed6b
    Added Reference https://git.kernel.org/stable/c/fbf0591275f50eae5733c3d7a8cd6c1e79933ffa
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 5.5
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact