better-auth versions before 1.1.20 contain a bypass vulnerability in trustedOrigins validation logic affecting absolute URLs and wildcard domains. Attackers can construct malicious callbackURL parameters that pass origin checks and trigger open redirects to steal sensitive tokens for account takeover.
https://www.vulncheck.com/advisories/better-auth-before-open-redirect-via-trustedorigins-bypass
https://github.com/better-auth/better-auth/security/advisories/GHSA-vp58-j275-797x
Published: 2026-08-01
Updated: 2026-08-01
Base Score: 8.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:C/A:N
Severity: High
Base Score: 7.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
Severity: High
Base Score: 7.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High