{"id":"PYSEC-2026-1362","summary":"FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation","details":"Versions of the package fastapi-sso before 0.19.0 are vulnerable to Cross-site Request Forgery (CSRF) due to the improper validation of the OAuth state parameter during the authentication callback. While the get_login_url method allows for state generation, it does not persist the state or bind it to the user's session. Consequently, the verify_and_process method accepts the state received in the query parameters without verifying it against a trusted local value. This allows a remote attacker to trick a victim into visiting a malicious callback URL, which can result in the attacker's account being linked to the victim's internal account.","aliases":["CVE-2025-14546","GHSA-hp6r-r9vc-q8wx"],"modified":"2026-07-07T17:47:35.987584320Z","published":"2026-07-07T16:03:13.588483Z","references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-14546"},{"type":"WEB","url":"https://github.com/tomasvotava/fastapi-sso/issues/266"},{"type":"WEB","url":"https://github.com/tomasvotava/fastapi-sso/commit/6117d1a5ad498ba57d671e8a059ebe20db5abe02"},{"type":"PACKAGE","url":"https://github.com/tomasvotava/fastapi-sso"},{"type":"WEB","url":"https://security.snyk.io/vuln/SNYK-PYTHON-FASTAPISSO-14386403"},{"type":"PACKAGE","url":"https://pypi.org/project/fastapi-sso"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-hp6r-r9vc-q8wx"}],"affected":[{"package":{"name":"fastapi-sso","ecosystem":"PyPI","purl":"pkg:pypi/fastapi-sso"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.19.0"}]}],"versions":["0.10.0","0.11.0","0.12.0","0.12.1","0.12.2","0.13.0","0.13.1","0.14.0","0.14.1","0.14.2","0.15.0","0.16.0","0.17.0","0.18.0","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.4.0","0.5.0","0.5.1","0.6.1","0.6.2","0.6.3","0.6.4","0.7.0","0.7.1","0.7.2","0.7.3","0.7.4","0.8.0","0.9.0","0.9.1"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/fastapi-sso/PYSEC-2026-1362.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:P"}]}