better-auth versions before 1.4.9 contain a two-factor authentication bypass vulnerability when session.cookieCache is enabled. Attackers with valid primary credentials can access authenticated routes without completing second-factor verification by exploiting premature session caching.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:HVI:NVA:NSubsequent System
SC:NSI:NSA:N7.1/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NOther