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.

Attack Vector Network

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00288.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
better-auth better-auth unaffected
Version Status Constraints
1.5.0-beta.12 affected < 1.7.7
1.7.7 unaffected —

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

No data.

Project Subscriptions

Vendors Products
Better-auth Subscribe
Better Auth Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/better-auth/better-auth/security/advisories/GHSA-r4xp-prcw-77qf cve-icon cve-icon
https://www.vulncheck.com/advisories/better-auth-1.5.0-beta.12-before-1.7.7-authentication-bypass-via-oauth-proxy cve-icon cve-icon
History

Thu, 15 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Wed, 14 Oct 2026 23:00:00 +0000

Type Values Removed Values Added
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.
Title Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy
First Time appeared Better-auth
Better-auth better Auth
Weaknesses CWE-287
CPEs cpe:2.3:a:better-auth:better_auth:*:*:*:*:*:*:*:*
Vendors & Products Better-auth
Better-auth better Auth
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'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'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-15T15:36:16.330Z

Reserved: 2026-10-14T22:18:33.239Z

Link: CVE-2026-110864

cve-icon Vulnrichment

Updated: 2026-10-15T15:36:12.403Z

cve-icon NVD

Status : Deferred

Published: 2026-10-14T23:17:27.970

Modified: 2026-10-16T18:25:45.343

Link: CVE-2026-110864

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-15T12:15:06Z

Weaknesses