CVE-2026-31637 rxrpc: reject undecryptable rxkad response tickets

What is CVE-2026-31637?

CVE-2026-31637 is a critical vulnerability in Linux kernel, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-754

Which versions are affected by CVE-2026-31637?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31637?

Apply the vendor's patch.

Is CVE-2026-31637 being exploited?

There is no known exploitation of CVE-2026-31637 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-83696, BELL-CVE-2026-31637, DEBIAN-CVE-2026-31637, GHSA-45qq-4p94-jp2v, ROOT-OS-DEBIAN-11-CVE-2026-31637, ROOT-OS-DEBIAN-12-CVE-2026-31637 and 4 more.