CVE-2026-40574

MEDIUM EPSS 11.0%
Published Apr 21, 20262mo ago · Modified Jun 17, 20261w ago
6.8 CVSS 3.1
Medium
Find Similar
Published Apr 21, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

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 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 Details

Base Score
6.8
Exploitability
1.6
Impact
5.2
Vector string
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

Threat Intelligence

EPSS Exploit Probability
11.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-863 Incorrect Authorization Authorization

Affected Products 1

VendorProductVersionRange
oauth2_proxy_projectoauth2_proxy* <7.15.2

References 1

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

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.