CVE-2026-40574

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Source
https://cve.org/CVERecord?id=CVE-2026-40574
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40574.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-40574
Aliases
Downstream
Related
Published
2026-04-21T16:32:34Z
Modified
2026-08-12T03:51:27Z
Severity
  • 6.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
OAuth2 Proxy has an Authorization Bypass in Email Domain Validation via Malformed Multi-@ Email Claims
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40574.json"
}
References

Affected packages

Git / github.com/oauth2-proxy/oauth2-proxy

Affected ranges

Type
GIT
Repo
https://github.com/oauth2-proxy/oauth2-proxy
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
5961fd99b42c3625b8ef08690d38be5cb37f44b0
Database specific
Show details 
{
    "cpe": "cpe:2.3:a:oauth2_proxy_project:oauth2_proxy:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "7.15.2"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ]
}

Affected versions

v1.*
v1.0
v1.1
v1.1.1
v2.*
v2.0
v2.0.1
v2.1
v2.2
v3.*
v3.0.0
v3.1.0
v3.2.0
v4.*
v4.0.0
v4.1.0
v5.*
v5.0.0
v5.1.0
v6.*
v6.0.0
v6.1.0
v6.1.1
v7.*
v7.0.0
v7.0.1
v7.1.0
v7.1.1
v7.1.2
v7.1.3
v7.10.0
v7.11.0
v7.12.0
v7.13.0
v7.14.0
v7.14.1
v7.14.2
v7.14.3
v7.15.0
v7.15.1
v7.2.0
v7.2.1
v7.3.0
v7.4.0
v7.5.0
v7.5.1
v7.6.0
v7.7.0
v7.7.1
v7.8.0
v7.8.1
v7.8.2
v7.9.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-40574.json"