{"cve":"CVE-2024-40627","nvd":{"published":"2024-07-15T20:15:05.033","modified":"2026-06-17T07:46:11.900","status":"Deferred","description":"Fastapi OPA is an opensource fastapi middleware which includes auth flow. HTTP `OPTIONS` requests are always allowed by `OpaMiddleware`, even when they lack authentication, and are passed through directly to the application. `OpaMiddleware` allows all HTTP `OPTIONS` requests without evaluating it against any policy. If an application provides different responses to HTTP `OPTIONS` requests based on an entity existing (such as to indicate whether an entity is writable on a system level), an unauthenticated attacker could discover which entities exist within an application. This issue has been addressed in release version 2.0.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N","score":5.8},"cwes":["CWE-204"],"references":["https://github.com/busykoala/fastapi-opa/blob/6dd6f8c87e908fe080784a74707f016f1422b58a/fastapi_opa/opa/opa_middleware.py#L79-L80","https://github.com/busykoala/fastapi-opa/commit/9588109ff651f7ffc92687129c4956126443fb8c","https://github.com/busykoala/fastapi-opa/security/advisories/GHSA-5f5c-8rvc-j8wf","https://github.com/busykoala/fastapi-opa/blob/6dd6f8c87e908fe080784a74707f016f1422b58a/fastapi_opa/opa/opa_middleware.py#L79-L80","https://github.com/busykoala/fastapi-opa/commit/9588109ff651f7ffc92687129c4956126443fb8c"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:52:42.518321223+00:00"},"epss":{"cve":"CVE-2024-40627","score":0.00563,"percentile":0.46817,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5f5c-8rvc-j8wf","url":"https://osv.dev/vulnerability/GHSA-5f5c-8rvc-j8wf","summary":"OpaMiddleware does not filter HTTP OPTIONS requests","modified":"2026-09-10T03:50:16.471493528Z","packages":[{"ecosystem":"PyPI","name":"fastapi-opa","purl":"pkg:pypi/fastapi-opa","ranges":["<2.0.1"],"fixed":["2.0.1"]}]},{"id":"PYSEC-2026-1361","url":"https://osv.dev/vulnerability/PYSEC-2026-1361","summary":"OpaMiddleware does not filter HTTP OPTIONS requests","modified":"2026-07-07T17:47:35.983543869Z","packages":[{"ecosystem":"PyPI","name":"fastapi-opa","purl":"pkg:pypi/fastapi-opa","ranges":["<2.0.1"],"fixed":["2.0.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}