Vulnerability · Published Oct 14, 2026 · Assigned by VulnCheck

CVE-2026-110864Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy

High 7.4

In plain English

A high-severity improper authentication in better-auth from better-auth. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High

Exploit odds (30 days)0.3%top 78.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	better-auth	1.7.7	GHSA-r4xp-prcw-77qf

Affected products (as reported)

Vendor	Product	Versions
better-auth	better-auth	1.5.0-beta.12 – before 1.7.7

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References

GitHub Security Advisory (GHSA-r4xp-prcw-77qf) vendor-advisory
VulnCheck Advisory: Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy third-party-advisory