{"id":"CVE-2025-14546","aliases":["EUVD-2025-204438","GHSA-hp6r-r9vc-q8wx","PYSEC-2026-1362"],"status":"published","title":"FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation","description":"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.","severity":{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00359,"percentile":0.29856,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-285"],"published":"2025-12-19T05:00:02Z","modified":"2026-10-28T02:30:42Z","fixes":[{"ecosystem":"PyPI","package":"fastapi-sso","fixed_in":["0.19.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"fastapi-sso","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.19.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"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"]},{"source":"osv","ecosystem":"PyPI","package":"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"]}],"references":[{"url":"https://security.snyk.io/vuln/SNYK-PYTHON-FASTAPISSO-14386403","tags":["web"]},{"url":"https://github.com/tomasvotava/fastapi-sso/commit/6117d1a5ad498ba57d671e8a059ebe20db5abe02","tags":["fix","web"]},{"url":"https://github.com/tomasvotava/fastapi-sso/issues/266","tags":["report","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-14546","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hp6r-r9vc-q8wx","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/14xxx/CVE-2025-14546.json","tags":["advisory"]},{"url":"https://github.com/tomasvotava/fastapi-sso","tags":["package"]},{"url":"https://pypi.org/project/fastapi-sso","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2025-14546","description":"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.","status":"published","published":"2025-12-19T05:00:02.151Z","modified":"2025-12-19T15:39:15.674Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium","assessor":"cna"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N/E:P","level":"medium","assessor":"cna"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T14:32:28.250136Z"}],"euvd":[{"id":"EUVD-2025-204438","description":"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.","status":"published","published":"2025-12-19T05:00:02Z","modified":"2025-12-19T15:39:15Z","cvss":[{"version":"4.0","score":6.9,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T19:49:02.571203Z"}],"ghsa":[{"id":"GHSA-hp6r-r9vc-q8wx","title":"FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation","description":"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.","status":"published","published":"2025-12-19T06:30:27Z","modified":"2025-12-19T21:08:33Z","cvss":[{"version":"4.0","score":5.4,"vector":"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","level":"medium"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T14:39:13.204325Z"}],"nvd":[{"id":"CVE-2025-14546","description":"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.","status":"published","published":"2025-12-19T05:16:09.497Z","modified":"2026-10-13T11:10:00.203Z","cvss":[{"version":"4.0","score":5.4,"vector":"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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T14:11:52.309391Z"}],"osv":[{"id":"CVE-2025-14546","description":"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.","status":"published","published":"2025-12-19T05:00:02.151Z","modified":"2026-10-28T02:30:42.065532835Z","cvss":[{"version":"4.0","score":5.4,"vector":"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","level":"medium"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T15:44:46.340268Z"},{"id":"GHSA-hp6r-r9vc-q8wx","title":"FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation","description":"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.","status":"published","published":"2025-12-19T06:30:27Z","modified":"2026-09-10T03:50:31.957663246Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N","level":"medium"},{"version":"4.0","score":5.4,"vector":"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","level":"medium"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T15:46:49.28217Z"},{"id":"PYSEC-2026-1362","title":"FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation","description":"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.","status":"published","published":"2026-07-07T16:03:13.588483Z","modified":"2026-07-07T17:47:35.98758432Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N","level":"medium"},{"version":"4.0","score":5.4,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T15:52:54.622769Z"}]}}