Critical · CVSS 9.1CVE-2026-110864

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

Answer in brief

CVE-2026-110864 records a Critical severity (CVSS 9.1) vulnerability in Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy. The current sources do not mark it as known exploited. The current feed maps better-auth/better-auth (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 14, 2026Updated Oct 14, 2026Source checked Oct 15, 2026First seen by HOL Oct 14, 2026Material review Oct 14, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps better-auth/better-auth (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
better-auth/better-authgeneric	>=1.5.0-beta.12 <1.7.7	1.7.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for better-auth/better-auth.
Review the reported fix. Update better-auth/better-auth to 1.7.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 14, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.