better-auth up to 1.7.0-beta.9 Middleware authorization

Summaryinfo

A vulnerability identified as critical has been detected in better-auth up to 1.7.0-beta.9. This vulnerability affects unknown code of the component Middleware. The manipulation leads to authorization. This vulnerability is traded as CVE-2026-67329. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in better-auth up to 1.7.0-beta.9. It has been rated as critical. This issue affects some unknown functionality of the component Middleware. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-639. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

@better-auth/stripe versions >= 1.4.11 and < 1.6.21, and >= 1.7.0-beta.0 and < 1.7.0-beta.10, contain an authorization bypass in organization subscription actions. The middleware validates the organization ID taken from the request query string against the authorizeReference callback, but the handler reads the organization ID only from the request body and falls back to the caller's active organization from their session. When these differ, an authenticated member of multiple organizations can perform subscription actions (cancel, change plan, restore, billing portal access) against an organization they belong to but should not manage, and can access another organization's billing details including payment methods, invoices, and subscription state.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-67329 since 07/29/2026. The exploitation is known to be easy. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/01/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-51806). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• better-auth

Version

• 1.7.0-beta.0
• 1.7.0-beta.1
• 1.7.0-beta.2
• 1.7.0-beta.3
• 1.7.0-beta.4
• 1.7.0-beta.5
• 1.7.0-beta.6
• 1.7.0-beta.7
• 1.7.0-beta.8
• 1.7.0-beta.9

Website

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

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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