CVE-2026-31640: rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial
In rxrpcpostresponse(), the code should be comparing the challenge serial number from the cached response before deciding to switch to a newer response, but looks at the newer packet private data instead, rendering the comparison always false.
Fix this by switching to look at the older packet.
Fix further[1] to substitute the new packet in place of the old one if newer and also to release whichever we don't use.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-31640?
CVE-2026-31640 has been classified as a medium severity vulnerability.
How do I fix CVE-2026-31640?
To fix CVE-2026-31640, update the Linux kernel to a version that includes the patch for this vulnerability.
Which versions of the Linux kernel are affected by CVE-2026-31640?
CVE-2026-31640 affects Linux kernel versions between 6.16.1 and 6.19.13, as well as specific 7.0 release candidates.
What type of vulnerability is CVE-2026-31640?
CVE-2026-31640 is a coding error in the rxrpc module related to the handling of challenge serial numbers.
Is there a known exploit for CVE-2026-31640?
As of now, there are no publicly known exploits for CVE-2026-31640.