CVE-2026-67328

High

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.

SeverityHigh

CVSS8.1

Exploit probability—

ProductBetter-auth Sso

PublishedAug 1, 2026

First seenAug 1, 2026

Weakness typeCWE-79Cross-site scripting (XSS)

How to fix

Update

better-auth sso1.6.21, 1.7.0-beta.10 or later

Vendor advisories

github.com/better-auth/better-auth/security/advisories/GHSA-prpr-5gj3-qqhg

Affected products

Product	Affected versions	Fixed in
better-auth sso	v < 1.6.21, 1.7.0-beta.0 ≤ v < 1.7.0-beta.10	1.6.21, 1.7.0-beta.10

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