MEDIUM · 6.8

CVE-2026-40574

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 ...

Vulnerability 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.

CVSS Score

6.8

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE

Affected Products

VendorProductVersions
Oauth2 Proxy ProjectOauth2 Proxy< 7.15.2

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-40574?

CVE-2026-40574 is a vulnerability with a CVSS score of 6.8 (MEDIUM). 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 ...

How severe is CVE-2026-40574?

CVE-2026-40574 has been rated MEDIUM with a CVSS base score of 6.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-40574?

Check the references section above for vendor advisories and patch information. Affected products include: Oauth2 Proxy Project Oauth2 Proxy.