rxrpc: reject undecryptable rxkad response tickets

Summary

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.

Timeline

1. Apr 24, 2026, 2:44 PM UTCCVE published
2. Oct 16, 2026, 3:11 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Oct 19, 2026, 6:56 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in 252157d939d179b5d767cb860ff8fa7f8723b67a; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in a75b3b361dd481d942c5f259a82d59718a41092c; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in b3a808cd0790b5075aaa2bc3588edf02cd71d352; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in 47073aab8a3a5a7b41c9bd37d2a3dcbeeccd6c8a; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in a149dcae23309df9de1c3b6b5d468610ef5ab7de; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in 22f6258e7b31dba9bf88dce4e3ee7f0f20072e60; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in 58fcd1b156152613ba00a064a129fb69507ddd7d; From 17926a79320afa9b95df6b977b40cca6d8713cea · fixed in fe4447cd95623b1cfacc15f280aab73a6d7340b2

• Linux Linux

  2.6.22

• KernelLinux

  From 2.6.22 · fixed in 5.10.258; From 5.11.0 · fixed in 5.15.209; From 5.16.0 · fixed in 6.1.175; From 6.2.0 · fixed in 6.6.135; From 6.7.0 · fixed in 6.12.82; From 6.13.0 · fixed in 6.18.23; From 6.19.0 · fixed in 6.19.13

References 8