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 attacker may be able to authenticate with an email claim such as attacker@evil.com@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 v3 6.8 MEDIUM

6.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-c5c4-8r6x-56w3	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:oauth2_proxy_project:oauth2_proxy:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-04-21 17:16

Updated : 2026-06-17 10:45

NVD link : CVE-2026-40574

Mitre link : CVE-2026-40574

CVE.ORG link : CVE-2026-40574

JSON object : View

Products Affected

oauth2_proxy_project

oauth2_proxy

CWE

CWE-863

Incorrect Authorization

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