Linux Kernel up to 6.18.22/6.19.12 rxrpc initialization

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.18.22/6.19.12 and classified as critical. Affected by this vulnerability is an unknown functionality of the component rxrpc. The manipulation leads to initialization. This vulnerability is traded as CVE-2026-31676. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.22/6.19.12. This issue affects an unknown part of the component rxrpc. The manipulation with an unknown input leads to a initialization vulnerability. Using CWE to declare the problem leads to CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: rxrpc: only handle RESPONSE during service challenge Only process RESPONSE packets while the service connection is still in RXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before running response verification and security initialization, then use a local secured flag to decide whether to queue the secured-connection work after the state transition. This keeps duplicate or late RESPONSE packets from re-running the setup path and removes the unlocked post-transition state test.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-31676 since 03/09/2026. The exploitation is known to be easy. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/04/2026).

The vulnerability scanner Nessus provides a plugin with the ID 310340 (Linux Distros Unpatched Vulnerability : CVE-2026-31676), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.18.23 or 6.19.13 eliminates this vulnerability. Applying the patch d0035e634dae83237ab7f5681eb52b2f65d0ceb8/03fd2ef73cb4ffd0af100a95b634af54f474414e/c43ffdcfdbb5567b1f143556df8a04b4eeea041c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (310340) and EUVD (EUVD-2026-25643). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.19.0
• 6.19.1
• 6.19.2
• 6.19.3
• 6.19.4
• 6.19.5
• 6.19.6
• 6.19.7
• 6.19.8
• 6.19.9
• 6.19.10
• 6.19.11
• 6.19.12

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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