Vulnerability in Linux

CVE-2026-31640

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial In rxrpc_post_response(), 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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-31640: held from 0.004 to 0.006.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

  • Linux — versions 5800b1cf3fd8ccab752a101865be1e76dac33142, 6.16, 0
  • Linux Kernel — versions 6.16, 7.0

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31640?
CVE-2026-31640 is a high-severity vulnerability in Linux, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-04-24.
How severe is CVE-2026-31640?
High severity. CVSS v3 base score is 7.5 out of 10.