{"cve":"CVE-2023-22465","nvd":{"published":"2023-01-04T16:15:09.323","modified":"2026-06-17T05:35:30.800","status":"Modified","description":"Http4s is a Scala interface for HTTP services. Starting with version 0.1.0 and prior to versions 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38, the `User-Agent` and `Server` header parsers are susceptible to a fatal error on certain inputs.  In http4s, modeled headers are lazily parsed, so this only applies to services that explicitly request these typed headers. Fixes are released in 0.21.34, 0.22.15, 0.23.17, and 1.0.0-M38. As a workaround, use the weakly typed header interface.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","score":5.3},"cwes":["CWE-20"],"references":["https://github.com/http4s/http4s/security/advisories/GHSA-54w6-vxfh-fw7f","https://github.com/http4s/http4s/security/advisories/GHSA-54w6-vxfh-fw7f"],"products":["typelevel:http4s"],"source":"nvd","synced_at":"2026-10-19T21:37:31.370122805+00:00"},"epss":{"cve":"CVE-2023-22465","score":0.00854,"percentile":0.58307,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-54w6-vxfh-fw7f","url":"https://osv.dev/vulnerability/GHSA-54w6-vxfh-fw7f","summary":"Http4s improperly parses User-Agent and Server headers","modified":"2025-12-11T21:03:44.483986Z","packages":[{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.13","purl":"pkg:maven/org.http4s/http4s-core_2.13","ranges":[">=0.1.0 <0.21.34"],"fixed":["0.21.34"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.13","purl":"pkg:maven/org.http4s/http4s-core_2.13","ranges":[">=0.22.0 <0.22.15"],"fixed":["0.22.15"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.13","purl":"pkg:maven/org.http4s/http4s-core_2.13","ranges":[">=0.23.0 <0.23.17"],"fixed":["0.23.17"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.13","purl":"pkg:maven/org.http4s/http4s-core_2.13","ranges":[">=1.0.0-M1 <1.0.0-M38"],"fixed":["1.0.0-M38"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.10","purl":"pkg:maven/org.http4s/http4s-core_2.10","ranges":[">=0.1.0 <=0.9.3"],"fixed":[]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.11","purl":"pkg:maven/org.http4s/http4s-core_2.11","ranges":[">=0.1.0 <=0.21.0-M1"],"fixed":[]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.12","purl":"pkg:maven/org.http4s/http4s-core_2.12","ranges":[">=0.1.0 <0.21.34"],"fixed":["0.21.34"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.12","purl":"pkg:maven/org.http4s/http4s-core_2.12","ranges":[">=0.22.0 <0.22.15"],"fixed":["0.22.15"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core_2.12","purl":"pkg:maven/org.http4s/http4s-core_2.12","ranges":[">=0.23.0 <0.23.17"],"fixed":["0.23.17"]},{"ecosystem":"Maven","name":"org.http4s:http4s-core","purl":"pkg:maven/org.http4s/http4s-core","ranges":[">=1.0.0-M1 <=1.0.0-M30"],"fixed":[]}]}],"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."]}