CVE-2025-71403 PUBLISHED

better-auth before 1.1.20 Open Redirect via trustedOrigins Bypass

Assigner: VulnCheck
Reserved: 18.07.2026 Published: 01.08.2026 Updated: 01.08.2026

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.

CVSS 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
CVSS Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N
CVSS Score: 7.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	better-auth
Product	better-auth
Versions	Default: unaffected affected from 0 to 1.1.20 (excl.) Version 1.1.20 is unaffected

CVE-2025-71403 PUBLISHED

better-auth before 1.1.20 Open Redirect via trustedOrigins Bypass

Metrics

Product Status

Credits

References

Problem Types