CVE-2026-67328

@better-auth/sso before 1.6.21 Account Takeover via SSO

State: Published
Severity: 8.6 High
Published: Aug 1, 2026
Updated: Oct 8, 2026
Reserved: Jul 29, 2026

Description

@better-auth/sso versions before 1.6.21 contain multiple authentication bypass vulnerabilities in SSO provider handling that allow attackers to sign in as arbitrary users. Attackers can exploit domain verification parsing mismatches, orphaned provider accounts, unbound SAML assertions, or reflected XSS on logout endpoints to gain unauthorized session access and account takeover.

Scores

CVSS	Score	Vector	Source
4.0	8.6 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N	VulnCheck
3.1	8.1 High	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N	VulnCheck

Weaknesses

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected Products

Product	Versions
ssobetter-auth	before 1.6.21Affected 1.6.21Not affected
ssobetter-auth	1.7.0-beta.0 to before 1.7.0-beta.10Affected 1.7.0-beta.10Not affected

References

GitHub Security Advisory (GHSA-prpr-5gj3-qqhg)vendor-advisory
VulnCheck Advisory: @better-auth/sso before 1.6.21 Account Takeover via SSOthird-party-advisory

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