{"cve":{"cve_id":"CVE-2026-47778","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":null,"epss_percentile":null,"epss_as_of":null,"description":"Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a structural flaw was identified in DefaultCertValidator::verifySubjectAltName where the extracted DNS SAN string is cast to a C-style string using .c_str() before being passed to the Utility::dnsNameMatch() algorithm. If the attacker serves a certificate with a dNSName SAN containing an embedded NUL byte, the helper Utility::generalNameAsString captures the complete string including the NUL. However, when .c_str() evaluates it, implicit conversion to absl::string_view inside dnsNameMatch relies on strlen(), prematurely truncating the evaluation context. Envoy evaluates trucated string against the exact required config_san match and returns true, thereby successfully validating the string with the Nul byte for an upstream routing. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.","published_at":"2026-06-26T17:27:57.707000Z","last_modified_at":null,"cvss_v3_score":4.4,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-158"],"nvd_references":["https://github.com/envoyproxy/envoy/security/advisories/GHSA-f8x4-rw5x-f3r7"],"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":"2026-06-28T17:54:57.553414Z","updated_at":"2026-06-28T23:30:42.157376Z"},"effective_severity":"MEDIUM","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":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"H","value_label":"High"},{"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":"N","value_label":"None"},{"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":">= 1.38.0, < 1.38.1","version_start_inclusive":true,"version_end":">= 1.38.0, < 1.38.1","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.38.0, < 1.38.1:>= 1.38.0, < 1.38.1"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":">= 1.37.0, < 1.37.3","version_start_inclusive":true,"version_end":">= 1.37.0, < 1.37.3","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.37.0, < 1.37.3:>= 1.37.0, < 1.37.3"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":">= 1.36.0, < 1.36.7","version_start_inclusive":true,"version_end":">= 1.36.0, < 1.36.7","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:>= 1.36.0, < 1.36.7:>= 1.36.0, < 1.36.7"},{"vendor_slug":"envoyproxy","vendor_name":"envoyproxy","product_slug":"envoy","product_name":"envoy","version_start":"< 1.35.11","version_start_inclusive":true,"version_end":"< 1.35.11","version_end_inclusive":true,"cpe23_uri":"cve5:envoyproxy:envoy:< 1.35.11:< 1.35.11"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-f8x4-rw5x-f3r7","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-06-26T17:27:57.707000Z","label":"CVE published","source":null}]}