CVE-2026-40574
Description
OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Prior to 7.15.2, an authorization bypass exists in OAuth2 Proxy as part of the email_domain enforcement option. An attacker may be able to authenticate with an email claim such as [email protected]@company.com and satisfy an allowed domain check for company.com, even though the claim is not a valid email address. The issue ONLY affects deployments that rely on email_domain restrictions and accept email claim values from identity providers or claim mappings that do not strictly enforce normal email syntax. This vulnerability is fixed in 7.15.2.
How to fix
- oauth2_proxy_project oauth2_proxy7.15.2 or later
- github.com/oauth2-proxy/oauth2-proxy/v77.15.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| oauth2_proxy_project oauth2_proxy | v < 7.15.2 | 7.15.2 |
| github.com/oauth2-proxy/oauth2-proxy/v7Go | v < 7.15.2 | 7.15.2 |
| github.com/oauth2-proxy/oauth2-proxyGo | No range specified | — |
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