CVE-2026-49423

Name of the Vulnerable Software and Affected Versions FreeBSD (affected versions not specified)

Description A flaw in the KTLS (Kernel TLS) subsystem occurs when building the iovec array for a received TLS 1.2 CBC record. The function ktls ocf tls cbc decrypt() increments the iovec index for every mbuf in the chain, including those skipped for containing only TLS header bytes, which leaves uninitialized entries in the iovec array because it was allocated without zeroing. A remote TLS peer can trigger a kernel panic by controlling TCP segmentation so that the first mbuf of a CBC record contains only the 5-byte TLS record header, causing the kernel to read from these uninitialized entries during HMAC computation.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.