In the Linux kernel, the following vulnerability has been resolved: crypto: krb5enc - fix async decrypt skipping hash verification krb5enc_dispatch_decrypt() sets req->base.complete as the skcipher callback, which is the caller's own completion handler. When the skcipher completes asynchronously, this signals "done" to the caller without executing krb5enc_dispatch_decrypt_hash(), completely bypassing the integrity verification (hash check). Compare with the encrypt path which correctly uses krb5enc_encrypt_done as an intermediate callback to chain into the hash computation on async completion. Fix by adding krb5enc_decrypt_done as an intermediate callback that chains into krb5enc_dispatch_decrypt_hash() upon async skcipher completion, matching the encrypt path's callback pattern. Also fix EBUSY/EINPROGRESS handling throughout: remove krb5enc_request_complete() which incorrectly swallowed EINPROGRESS notifications that must be passed up to callers waiting on backlogged requests, and add missing EBUSY checks in krb5enc_encrypt_ahash_done for the dispatch_encrypt return value. Unset MAY_BACKLOG on the async completion path so the user won't see back-to-back EINPROGRESS notifications.
ZDI discloses a Linux kernel crypto subsystem use-after-free (CVE-2026-31719, CVSS 8.8) letting local low-privileged attackers escalate to root.
ZDI advisory ZDI-26-680 covers a use-after-free vulnerability in the Linux kernel crypto subsystem, tracked as CVE-2026-31719 with a CVSS score of 8.8. A local attacker who can already execute low-privileged code can exploit it to escalate privileges on affected installations. The advisory does not report any exploitation in the wild.