CVE-2026-68124

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

Description An out-of-bounds heap write exists in the MCTP serial receive state machine. The issue occurs in the mctp serial push header() function when a frame length byte of zero is processed. Because the validation only checks the upper bound, a length of zero allows the state machine to advance to STATE DATA with rxlen set to 0. In the mctp serial push() function, the condition to transition out of STATE DATA is never met because the position counter is incremented before the check, leading to an unbounded write beyond the 74-byte rxbuf buffer. Exploiting this requires CAP NET ADMIN privileges to attach the N MCTP line discipline and activate the mctpserialN network device.

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