CVE-2026-26308: falha de alta gravidade em envoyproxy envoy
Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation
Publicada em
Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.
21Vexday Risk Score
Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.
ssvc Trackcvss 7.5epss 0.3%
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—specifically "Deny" rules—by 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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N
Produtos afetados
envoyproxy · envoyCVEs relacionadas — envoyproxy envoy
No mesmo produto, das mais perigosas para as menos.
CVE-2024-30255MEDIUMHTTP/2: CPU exhaustion due to CONTINUATION frame floodEPSS 85.0%CVE-2024-27919HIGHHTTP/2: memory exhaustion due to CONTINUATION frame floodEPSS 83.9%CVE-2021-29492HIGHBypass of path matching rules using escaped slash charactersEPSS 63.1%CVE-2021-32777HIGHIncorrect concatenation of multiple value request headers in ext-authz extensionEPSS 3.3%CVE-2021-21378HIGHJWT authentication bypass with unknown issuer tokenEPSS 1.7%CVE-2023-35945HIGHEnvoy vulnerable to HTTP/2 memory leak in nghttp2 codecEPSS 1.7%