by Kastro
Paper/Archive/CVE-2026-31637

CVE-2026-31637

Linux Linux — rxrpc: reject undecryptable rxkad response tickets

EPSS 0.6%CVSS 9.8
critical.is priorityof 100
39
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 48.2.482 × 209.6No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < 252157d939d179b5d767cb860ff8fa7f8723b67a252157d939d179b5d767cb860ff8fa7f8723b67aCNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < a75b3b361dd481d942c5f259a82d59718a41092ca75b3b361dd481d942c5f259a82d59718a41092cCNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < b3a808cd0790b5075aaa2bc3588edf02cd71d352b3a808cd0790b5075aaa2bc3588edf02cd71d352CNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < 47073aab8a3a5a7b41c9bd37d2a3dcbeeccd6c8a47073aab8a3a5a7b41c9bd37d2a3dcbeeccd6c8aCNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < a149dcae23309df9de1c3b6b5d468610ef5ab7dea149dcae23309df9de1c3b6b5d468610ef5ab7deCNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < 22f6258e7b31dba9bf88dce4e3ee7f0f20072e6022f6258e7b31dba9bf88dce4e3ee7f0f20072e60CNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < 58fcd1b156152613ba00a064a129fb69507ddd7d58fcd1b156152613ba00a064a129fb69507ddd7dCNA
Linux17926a79320afa9b95df6b977b40cca6d8713cea – < fe4447cd95623b1cfacc15f280aab73a6d7340b2fe4447cd95623b1cfacc15f280aab73a6d7340b2CNA
Linux2.6.22–CNA
SIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versions–siemens-SADP

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgit.kernel.org/stable/c/252157d939d179b5d767cb860ff8fa7f8723b67arefgit.kernel.org/stable/c/a75b3b361dd481d942c5f259a82d59718a41092crefgit.kernel.org/stable/c/b3a808cd0790b5075aaa2bc3588edf02cd71d352refgit.kernel.org/stable/c/47073aab8a3a5a7b41c9bd37d2a3dcbeeccd6c8arefgit.kernel.org/stable/c/a149dcae23309df9de1c3b6b5d468610ef5ab7derefgit.kernel.org/stable/c/22f6258e7b31dba9bf88dce4e3ee7f0f20072e60refgit.kernel.org/stable/c/58fcd1b156152613ba00a064a129fb69507ddd7drefgit.kernel.org/stable/c/fe4447cd95623b1cfacc15f280aab73a6d7340b2refcert-portal.siemens.com/productcert/html/ssa-784472.html