Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N N U N N H 7.5 .0033 25.7 —
AFFECTED Product Versions Fixed envoy >= 1.38.0, < 1.38.3 – —
TIMELINE May 18 Reserved by GitHub_M Jun 26 EXPLOIT PUBLISHED — CVE-2026-47221 (envoyproxy envoy). Public exploit reference added. Jun 26 Published (CNA: GitHub_M)
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.
| Date | Event | Detail |
|---|---|---|
| May 18, 2026 | Reserved | Reserved by GitHub_M |
| June 26, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-47221 (envoyproxy envoy). Public exploit reference added. |
| June 26, 2026 | Published | Published (CNA: GitHub_M) |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| envoyproxy | envoy | — | >= 1.38.0, < 1.38.3 | — |
Authoritative record: CVE-2026-47221 at cve.org
Vendors: envoyproxy
Weaknesses: CWE-476
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-47221 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.