OpenSSH before 10.3 mishandles the authorized_keys principals option in uncommon scenarios involving a principals list in conjunction with a Certificate Authority that makes certain use of comma characters.
Exploitability
AV:NAC:HPR:LUI:NScope
S:UImpact
C:LI:LA:N4.2/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:NOther