{"cve":"CVE-2021-39185","nvd":{"published":"2021-09-01T20:15:07.447","modified":"2026-06-17T04:03:16.257","status":"Modified","description":"Http4s is a minimal, idiomatic Scala interface for HTTP services. In http4s versions 0.21.26 and prior, 0.22.0 through 0.22.2, 0.23.0, 0.23.1, and 1.0.0-M1 through 1.0.0-M24, the default CORS configuration is vulnerable to an origin reflection attack. The middleware is also susceptible to a Null Origin Attack. The problem is fixed in 0.21.27, 0.22.3, 0.23.2, and 1.0.0-M25. The original `CORS` implementation and `CORSConfig` are deprecated. See the GitHub GHSA for more information, including code examples and workarounds.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1},"cwes":["CWE-346"],"references":["https://github.com/http4s/http4s/releases/tag/v0.23.2","https://github.com/http4s/http4s/security/advisories/GHSA-52cf-226f-rhr6","https://github.com/http4s/http4s/releases/tag/v0.23.2","https://github.com/http4s/http4s/security/advisories/GHSA-52cf-226f-rhr6"],"products":["typelevel:http4s"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-39185","score":0.00594,"percentile":0.484,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-52cf-226f-rhr6","url":"https://osv.dev/vulnerability/GHSA-52cf-226f-rhr6","summary":"Default CORS config allows any origin with credentials","modified":"2026-07-08T06:28:14.835239665Z","packages":[{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.13.0-M5","purl":"pkg:maven/org.http4s/http4s-server_2.13.0-M5","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_3","purl":"pkg:maven/org.http4s/http4s-server_3","ranges":[">=0.22.0 <0.22.3"],"fixed":["0.22.3"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_3","purl":"pkg:maven/org.http4s/http4s-server_3","ranges":[">=0.23.0 <0.23.2"],"fixed":["0.23.2"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.10","purl":"pkg:maven/org.http4s/http4s-server_2.10","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.11","purl":"pkg:maven/org.http4s/http4s-server_2.11","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.12","purl":"pkg:maven/org.http4s/http4s-server_2.12","ranges":["<0.21.27"],"fixed":["0.21.27"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.12","purl":"pkg:maven/org.http4s/http4s-server_2.12","ranges":[">=0.22.0 <0.22.3"],"fixed":["0.22.3"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.12","purl":"pkg:maven/org.http4s/http4s-server_2.12","ranges":[">=0.23.0 <0.23.2"],"fixed":["0.23.2"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.13","purl":"pkg:maven/org.http4s/http4s-server_2.13","ranges":["<0.21.27"],"fixed":["0.21.27"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.13","purl":"pkg:maven/org.http4s/http4s-server_2.13","ranges":[">=0.22.0 <0.22.3"],"fixed":["0.22.3"]},{"ecosystem":"Maven","name":"org.http4s:http4s-server_2.13","purl":"pkg:maven/org.http4s/http4s-server_2.13","ranges":[">=0.23.0 <0.23.2"],"fixed":["0.23.2"]}]}],"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."]}