CVE-2026-47221
highpriority · track · 30EPSS 0.004 · 39 %ileDEEUUSEPSS · scored 2026-10-27
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.18.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the router filter contains a null pointer dereference vulnerability when handling HTTP 303 (See Other) internal redirects for body-less non-GET/HEAD requests. When a POST, PUT, DELETE, or PATCH request without a body is sent to a route configured with internal redirect policy that includes 303 in redirect_response_codes, and the upstream responds with HTTP 303, the redirect handling code attempts to drain a request body buffer that was never allocated. This results in a segmentation fault that crashes the entire Envoy process. When route configured with internal_redirect_policy including 303 in redirect_response_codes and upstream must return HTTP 303 response, an unauthenticated attacker can exploit this to cause complete denial of service, terminating all active connections. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.9–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (22)
Products and version ranges known to be affected.
- Google Cloud Platform managed Cloud Service Meshall versionscert_bundDEcpe:/a:google:cloud_platform:managed_cloud_service_mesh
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-2048Google Cloud Service Mesh und Envoy Proxy: Mehrere SchwachstellenDeutsch2026-06-23csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Google Cloud Service Mesh und Envoy Proxy ausnutzen, um einen Denial-of-Service-Zustand zu verursachen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen oder andere, nicht näher bezeichnete Angriffe durchzuführen.
- BIT-envoy-2026-47221Envoy: Null pointer deref in internal redirects2026-06-29vendor · osvUS
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.18.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the router filter contains a null pointer dereference vulnerability when handling HTTP 303 (See Other) internal redirects for body-less non-GET/HEAD requests. When a POST, PUT, DELETE, or PATCH request without a body is sent to a route configured with internal redirect policy that includes 303 in redirect_response_codes, and the upstream responds with HTTP 303, the redirect handling code attempts to drain a request body buffer that was never allocated. This results in a segmentation fault that crashes the entire Envoy process. When route configured with internal_redirect_policy including 303 in redirect_response_codes and upstream must return HTTP 303 response, an unauthenticated attacker can exploit this to cause complete denial of service, terminating all active connections. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (3)
External citations — patches, advisories, analysis.
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