yasm v1.3.0 was discovered to contain a use after free via the function expand_mmac_params at /nasm/nasm-pp.c.
Created yasm tracking bugs for this issue:
Affects: epel-all [bug 2208606]
Affects: fedora-all [bug 2208607]
This should be rejected as per yasm security policy, unless there's a way this could be exploited using *trusted* input: