{"id":"BIT-oauth2-proxy-2026-40574","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.","aliases":["CVE-2026-40574","GHSA-c5c4-8r6x-56w3","GO-2026-5314"],"modified":"2026-09-08T08:48:10.868597681Z","published":"2026-04-23T08:47:00.871Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:oauth2_proxy_project:oauth2_proxy:*:*:*:*:*:go:*:*"]},"references":[{"type":"ADVISORY","url":"https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-c5c4-8r6x-56w3"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40574"}],"affected":[{"package":{"name":"oauth2-proxy","ecosystem":"Bitnami","purl":"pkg:bitnami/oauth2-proxy"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"7.15.2"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/oauth2-proxy/BIT-oauth2-proxy-2026-40574.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N"}]}],"schema_version":"1.9.0"}