{"cve":"CVE-2023-27491","nvd":{"published":"2023-04-04T19:15:07.150","modified":"2026-06-17T05:45:19.493","status":"Modified","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Compliant HTTP/1 service should reject malformed request lines. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, There is a possibility that non compliant HTTP/1 service may allow malformed requests, potentially leading to a bypass of security policies. This issue is fixed in versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9.","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-444","CWE-20"],"references":["https://datatracker.ietf.org/doc/html/rfc9113#section-8.3","https://datatracker.ietf.org/doc/html/rfc9114#section-4.3.1","https://github.com/envoyproxy/envoy/security/advisories/GHSA-5jmv-cw9p-f9rp","https://www.rfc-editor.org/rfc/rfc9110#section-5.6.2","https://datatracker.ietf.org/doc/html/rfc9113#section-8.3"],"products":["envoyproxy:envoy"],"source":"nvd","synced_at":"2026-10-19T21:37:48.383111019+00:00"},"epss":{"cve":"CVE-2023-27491","score":0.00869,"percentile":0.58787,"date":"2026-11-01"},"kev":null,"osv":[],"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."]}