Linux Kernel Vulnerability in xfrm State Construction

CVE-2026-80843

What is CVE-2026-80843?

A flaw within the Linux kernel's xfrm state construction process can lead to a memory leak involving the authentication algorithm. When the attach_auth_trunc() function allocates memory for the x->aalg variable, it may leave the x->props.aalgo field zero if the selected authentication algorithm lacks a valid sadb_alg_id, such as cmac(aes). This mismanagement of memory leads xfrm_state_construct() to erroneously assume no authentication algorithm is attached. Consequently, it overwrites the original allocation when attempting to attach an algorithm, which may be lost during subsequent operations. The flaw can lead to memory inefficiencies and potential security ramifications if not addressed.

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