In the GNU C Library (aka glibc or libc6) through 2.29, the memcmp function for the x32 architecture can incorrectly return zero (indicating that the inputs are equal) because the RDX most significant bit is mishandled.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H