Auth bypass in Better-Auth
CVE-2026-110864
Better Auth from 1.5.0-beta.12 before 1.7.7 contains an authentication bypass vulnerability in the OAuth Proxy plugin that allows unauthenticated attackers to sign in as other users by forging encrypted profiles. When the proxy shares the global secret and cookie-stored state is used, attackers can obtain encrypted state for a fake profile with a victim's verified email to take over the account via implicit linking.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/better-auth/better-auth/security/advisories/GHSA-r4xp-prcw-77qf (vendor-advisory)
- www.vulncheck.com/advisories/better-auth-1.5.0-beta.12-before-1.7.7-authenticat… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-110864?
- CVE-2026-110864 is a high-severity vulnerability in Better-Auth, classified under Improper Authentication. CVSS score: 7.4/10. Published 2026-10-14.
- How severe is CVE-2026-110864?
- High severity. CVSS v3 base score is 7.4 out of 10.