better-auth up to 1.6.12/1.7.0-beta.3 Oidc-provider redirect_uris

Summaryinfo

A vulnerability was found in better-auth up to 1.6.12/1.7.0-beta.3. It has been classified as problematic. This affects an unknown part of the component Oidc-provider. Performing a manipulation of the argument redirect_uris results in redirect. This vulnerability is cataloged as CVE-2026-67333. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as problematic has been found in better-auth up to 1.6.12/1.7.0-beta.3. This affects an unknown code block of the component Oidc-provider. The manipulation of the argument redirect_uris with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on integrity. The summary by CVE is:

better-auth before 1.6.13 (and pre-release builds 1.7.0-beta.0 through 1.7.0-beta.3) fail to validate the scheme of redirect_uris registered via the deprecated oidc-provider plugin and the mcp plugin (which wraps the same provider). An attacker can register an OAuth client with a javascript: redirect_uri, which the authorization server later returns unchanged in the consent response. If the deployment's consent page navigates the browser to the returned redirectURI (e.g. assigning it to window.location.href), the attacker's JavaScript executes in the authorization-server origin, exposing the victim's session and enabling account takeover.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-67333 since 07/29/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1204.001 according to MITRE ATT&CK.

Upgrading to version 1.6.13 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-51810). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• better-auth

Version

• 1.6.0
• 1.6.1
• 1.6.2
• 1.6.3
• 1.6.4
• 1.6.5
• 1.6.6
• 1.6.7
• 1.6.8
• 1.6.9
• 1.6.10
• 1.6.11
• 1.6.12
• 1.7.0-beta.0
• 1.7.0-beta.1
• 1.7.0-beta.2
• 1.7.0-beta.3

Website

• Product: https://github.com/better-auth/better-auth/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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