Bug 2461755 (CVE-2026-31676)

Summary: CVE-2026-31676 kernel: rxrpc: only handle RESPONSE during service challenge
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the `rxrpc` subsystem of the Linux kernel. This vulnerability allows for duplicate or late `RESPONSE` packets to be processed outside of the expected service challenging state. An attacker could potentially exploit this by sending specially crafted `RESPONSE` packets, leading to the re-execution of the setup path. This could result in unexpected system behavior or resource consumption.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-04-25 09:01:26 UTC 
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.
Comment 1 Alexander B 2026-04-27 10:07:39 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042543-CVE-2026-31676-ff79@gregkh/T