{"cve":{"cve_id":"CVE-2023-35944","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00598,"epss_percentile":0.43981,"epss_as_of":"2026-06-23","description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Envoy allows mixed-case schemes in HTTP/2, however, some internal scheme checks are case-sensitive. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, this can lead to the rejection of requests with mixed-case schemes such as `htTp` or `htTps`, or the bypassing of some requests such as `https` in unencrypted connections. With a fix in versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, Envoy will now lowercase scheme values by default, and change the internal scheme checks that were case-sensitive to be case-insensitive. There are no known workarounds for this issue.","published_at":"2023-07-25T18:35:59.135000Z","last_modified_at":null,"cvss_v3_score":8.2,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"poc","ssvc_automatable":false,"ssvc_technical_impact":"total","cwes":["CWE-20"],"nvd_references":["https://github.com/envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-29T01:33:13.861776Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":">= 1.26.0, < 1.26.4","version_start_inclusive":true,"version_end":">= 1.26.0, < 1.26.4","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.26.0, < 1.26.4:>= 1.26.0, < 1.26.4"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":">= 1.25.0, < 1.25.9","version_start_inclusive":true,"version_end":">= 1.25.0, < 1.25.9","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.25.0, < 1.25.9:>= 1.25.0, < 1.25.9"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":">= 1.24.0, < 1.24.10","version_start_inclusive":true,"version_end":">= 1.24.0, < 1.24.10","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.24.0, < 1.24.10:>= 1.24.0, < 1.24.10"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":"< 1.23.12","version_start_inclusive":true,"version_end":"< 1.23.12","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:< 1.23.12:< 1.23.12"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-pvgm-7jpg-pw5g","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2023-07-25T18:35:59.135000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:28:52.572229Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:28:52.572229Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:28:52.572229Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T01:33:13.861776Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:33:13.861776Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:33:13.861776Z","label":"SSVC decision revised","source":"vulnrichment"}]}