better-auth SSO race condition

Summaryinfo

A vulnerability described as problematic has been identified in better-auth. Affected by this issue is some unknown functionality of the component SSO. The manipulation results in race condition. This vulnerability is cataloged as CVE-2026-80192. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in better-auth (unknown version). It has been classified as problematic. Affected is an unknown code block of the component SSO. The manipulation with an unknown input leads to a race condition vulnerability. CWE is classifying the issue as CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

@better-auth/sso before 1.6.27 (and before 1.4.8 in the 1.4.x line and before 1.7.0-rc.5 in the 1.7 prerelease line) contains two domain-ownership flaws. When domain verification is disabled, automatic organization assignment accepts unverified provider domains, allowing an authenticated organization owner/administrator to register an SSO provider for an arbitrary domain and have users with matching email domains added to the attacker's organization with default member permissions. When domain verification is enabled, a race condition between the verify-domain and update-provider endpoints can apply completed DNS proof to a different domain; combined with implicit account linking, this can link an attacker-controlled identity provider to an existing user account. Exploitation requires the SSO plugin (and, for the org-assignment path, the organization plugin) with the relevant configuration enabled.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-80192 since 08/26/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Additional levels of successful authentication are needed for exploitation. There are neither technical details nor an exploit publicly available.

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

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

• better-auth

Website

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

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