CVE-2026-26308

{"id": "CVE-2026-26308", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 4.7, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.2, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 4.2, "exploitabilityScore": 3.9}]}, "published": "2026-03-10T20:16:35.707", "references": [{"url": "https://github.com/envoyproxy/envoy/commit/b6ba0b2294b98484fb0ed8556897d1073cc27867", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-ghc4-35x6-crw5", "tags": ["Exploit", "Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-863"}]}], "descriptions": [{"lang": "en", "value": "Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, the Envoy RBAC (Role-Based Access Control) filter contains a logic vulnerability in how it validates HTTP headers when multiple values are present for the same header name. Instead of validating each header value individually, Envoy concatenates all values into a single comma-separated string. This behavior allows attackers to bypass RBAC policies\u2014specifically \"Deny\" rules\u2014by sending duplicate headers, effectively obscuring the malicious value from exact-match mechanisms. This vulnerability is fixed in 1.37.1, 1.36.5, 1.35.8, and 1.34.13."}, {"lang": "es", "value": "Envoy es un proxy de alto rendimiento de borde/intermedio/servicio. Antes de 1.37.1, 1.36.5, 1.35.8 y 1.34.13, el filtro RBAC (control de acceso basado en roles) de Envoy contiene una vulnerabilidad l\u00f3gica en c\u00f3mo valida los encabezados HTTP cuando hay m\u00faltiples valores presentes para el mismo nombre de encabezado. En lugar de validar cada valor de encabezado individualmente, Envoy concatena todos los valores en una \u00fanica cadena separada por comas. Este comportamiento permite a los atacantes eludir las pol\u00edticas RBAC \u2014espec\u00edficamente las reglas de 'Denegar'\u2014 enviando encabezados duplicados, ocultando eficazmente el valor malicioso de los mecanismos de coincidencia exacta. Esta vulnerabilidad est\u00e1 corregida en 1.37.1, 1.36.5, 1.35.8 y 1.34.13."}], "lastModified": "2026-03-11T16:23:23.090", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C4169052-E37B-4577-8689-4DA8D6AFF3F3", "versionEndExcluding": "1.34.13"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "35DB0A9F-BCEA-48D7-97DE-A63FA24B2032", "versionEndExcluding": "1.35.8", "versionStartIncluding": "1.35.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B37DDD3B-8F92-4F76-B3B1-F3743CB41339", "versionEndExcluding": "1.36.5", "versionStartIncluding": "1.36.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:1.37.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C5266F62-E0D2-4525-90B6-65921EE14F79"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}