CVE-2026-31637: Linux Kernel

Critical severity, CVSS 9.8. EPSS: 0.8% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: rxrpc: reject undecryptable rxkad response tickets rxkad_decrypt_ticket() decrypts the RXKAD response ticket and then parses the buffer as plaintext without checking whether crypto_skcipher_decrypt() succeeded. A malformed RESPONSE can therefore use a non-block-aligned ticket length, make the decrypt operation fail, and still drive the ticket parser with attacker-controlled bytes. Check the decrypt result and abort the connection with RXKADBADTICKET when ticket decryption fails.

Affected products

• Linux Linux Kernel: from 2.6.22.1, before 6.6.135 (fixed in 6.6.135); from 6.7, before 6.12.82 (fixed in 6.12.82); from 6.13, before 6.18.23 (fixed in 6.18.23); from 6.19, before 6.19.13 (fixed in 6.19.13); version 2.6.22 only; version 7.0 only

Published 2026-04-24. Last modified 2026-06-17.