CVE-2026-48743

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{"affected": [{"affectedData": [{"product": "envoy", "vendor": "envoyproxy", "versions": [{"status": "affected", "version": ">= 1.38.0, < 1.38.1"}, {"status": "affected", "version": ">= 1.37.0, < 1.37.3"}, {"status": "affected", "version": ">= 1.36.0, < 1.36.7"}, {"status": "affected", "version": ">= 1.35.0, < 1.35.11"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "matchCriteriaId": "AB149324-8F14-48A5-ABC1-B4764A0BC33B", "versionEndExcluding": "1.35.13", "versionStartIncluding": "1.35.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "matchCriteriaId": "B1146A14-3C49-48C3-BC2A-1BBB202EBD84", "versionEndExcluding": "1.36.9", "versionStartIncluding": "1.36.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "matchCriteriaId": "2057BF79-00D1-4154-9DC0-3F278C72F4E1", "versionEndExcluding": "1.37.5", "versionStartIncluding": "1.37.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "matchCriteriaId": "2A218AD4-BF4B-46EA-96D7-3B25B7E71AC8", "versionEndExcluding": "1.38.3", "versionStartIncluding": "1.38.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1."}, {"lang": "es", "value": "Envoy es un proxy de borde y de servicio de c\u00f3digo abierto dise\u00f1ado para aplicaciones nativas de la nube. Antes de 1.35.11, 1.36.7, 1.37.3 y 1.38.1, Envoy puede traducir una solicitud HTTP/3 descendente que est\u00e1 completa en la capa de transporte (HEADERS con FIN / cierre solo de encabezados) pero que a\u00fan lleva una Content-Length distinta de cero en una solicitud HTTP/1 ascendente completa con deuda de cuerpo no resuelta. En una implementaci\u00f3n ascendente HTTP/1 donde el origen responde antes de leer el cuerpo declarado y mantiene la conexi\u00f3n reutilizable, el comienzo de la siguiente solicitud ascendente generada por Envoy puede ser consumido como el cuerpo de la primera solicitud. Los bytes restantes son entonces analizados por el origen como una nueva solicitud HTTP/1. Esto se reprodujo como un bypass de ruta/desincronizaci\u00f3n: el /pwn directo fue denegado por Envoy, pero el segundo flujo H3 descendente recibi\u00f3 la respuesta para el GET /pwn HTTP/1.1 analizado por el backend. Esta vulnerabilidad est\u00e1 corregida en 1.35.11, 1.36.7, 1.37.3 y 1.38.1."}], "id": "CVE-2026-48743", "lastModified": "2026-10-25T17:10:00.197", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "LOW", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 4.7, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-48743", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-06-29T15:04:55.378026Z", "version": "2.0.3"}}]}, "published": "2026-06-26T18:17:00.173", "references": [{"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory", "Mitigation"], "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Vendor Advisory", "Mitigation"], "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-444"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "envoy: Envoy: Request desynchronization allows security policy bypass via HTTP/3 to HTTP/1 translation", "id": "2494518", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2494518"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N", "status": "draft"}, "cwe": "CWE-444", "details": ["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, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.", "A flaw was found in Envoy, an open source edge and service proxy. This vulnerability occurs when Envoy translates an HTTP/3 request that is complete at the transport layer but still carries a nonzero Content-Length into an HTTP/1 request for an upstream server. If the upstream server responds before fully reading the declared body, a subsequent Envoy-generated request can be misinterpreted as part of the previous one. This can lead to a request desynchronization, allowing an attacker to bypass security policies and access unauthorized resources."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2026-48743", "package_state": [{"cpe": "cpe:/a:redhat:service_mesh:2", "fix_state": "Affected", "package_name": "openshift-service-mesh/proxyv2-rhel9", "product_name": "OpenShift Service Mesh 2"}, {"cpe": "cpe:/a:redhat:service_mesh:3", "fix_state": "Affected", "package_name": "openshift-service-mesh/istio-proxyv2-rhel9", "product_name": "OpenShift Service Mesh 3"}], "public_date": "2026-06-26T17:34:22Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-48743\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-48743\nhttps://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf"], "statement": "This is an Important flaw in Envoy, affecting Red Hat OpenShift Service Mesh and cloud.redhat.com deployments. The vulnerability arises from improper handling of HTTP/3 to HTTP/1 request translation, where a complete HTTP/3 request with a non-zero Content-Length can lead to request desynchronization on the upstream HTTP/1 server. This desynchronization allows an attacker to bypass security policies, potentially gaining unauthorized access to internal resources or services.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.38.0,1.38.1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.37.0,1.37.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.36.0,1.36.7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.35.0,1.35.11)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "envoy", "source": "cna", "vendor": "envoyproxy"}, "product": "envoy", "vendor": "envoyproxy"}], "created": "2026-06-26T19:45:04.139278+00:00", "updated": "2026-06-26T23:00:08.466666+00:00", "vendors": ["envoyproxy", "envoyproxy$PRODUCT$envoy"]}