Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck

CVE-2026-67332@better-auth/oauth-provider before 1.7.0-beta.4 Authorization Bypass

Medium 6.4

In plain English

A medium-severity security flaw in oauth-provider 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 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.4Medium

Exploit odds (30 days)0.3%top 82.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

@better-auth/oauth-provider before 1.7.0-beta.4 fails to bind access-token audience to the authorization grant, allowing clients to request tokens for unrelated resources. Attackers can complete an OAuth flow and obtain access tokens whose audience targets resource servers the authorization never covered, bypassing intended authorization boundaries.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@better-auth/oauth-provider	1.7.0-beta.4	GHSA-p2fr-6hmx-4528

Affected products (as reported)

Vendor	Product	Versions
better-auth	oauth-provider	1.4.8 – before 1.7.0-beta.4

Weakness: CWE-285 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-p2fr-6hmx-4528) vendor-advisory
VulnCheck Advisory: @better-auth/oauth-provider before 1.7.0-beta.4 Authorization Bypass third-party-advisory