{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-40574", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-14T13:24:29.474Z", "datePublished": "2026-04-21T16:32:34.537Z", "dateUpdated": "2026-04-21T16:32:34.537Z"}, "containers": {"cna": {"title": "OAuth2 Proxy has an Authorization Bypass in Email Domain Validation via Malformed Multi-@ Email Claims", "problemTypes": [{"descriptions": [{"cweId": "CWE-863", "lang": "en", "description": "CWE-863: Incorrect Authorization", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-c5c4-8r6x-56w3", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-c5c4-8r6x-56w3"}], "affected": [{"vendor": "oauth2-proxy", "product": "oauth2-proxy", "versions": [{"version": "< 7.15.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-04-21T16:32:34.537Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-c5c4-8r6x-56w3", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-40574", "lastModified": "2026-04-21T17:16:55.730", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-04-21T17:16:55.730", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-c5c4-8r6x-56w3"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-863"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}