CVE-2026-110864

critical

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.

References

https://www.vulncheck.com/advisories/better-auth-1.5.0-beta.12-before-1.7.7-authentication-bypass-via-oauth-proxy

https://github.com/better-auth/better-auth/security/advisories/GHSA-r4xp-prcw-77qf

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-101747

Details

Source: Mitre, NVD

Published: 2026-10-14

Updated: 2026-10-16

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.4

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

Severity: High

CVSS v4

Base Score: 9.1

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.00288