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Vulnerability · Published Sep 21, 2026 · Assigned by GitHub_M

CVE-2026-73513Envoy: oghttp2 upstream trailers incorrect handling

High 7.5

In plain English

A high-severity improper input validation in envoy from envoyproxy. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 57.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's optional oghttp2 upstream HTTP/2 codec accepts a response trailer HEADERS frame without END_STREAM. Envoy completes and deferred-deletes the ActiveRequest while oghttp2 keeps the stream open, leaving ClientStreamImpl with a dangling response_decoder_ reference. A later frame on the stream can dispatch through the freed object and crash the process. The relevant scope boundary is that the default nghttp2 codec rejects the malformed trailers, and the trigger is upstream-only with oghttp2 enabled. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

Affected products (as reported)

VendorProductVersions
envoyproxy envoy < 1.36.10>= 1.37.0, < 1.37.6>= 1.38.0, < 1.38.4>= 1.39.0, < 1.39.1

Weakness: CWE-20, CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References