CVE-2026-73513

7.5 HIGHpublic exploit available

Published 2026-09-21 · Updated 2026-09-21

AI risk analysis

Summary: The flaw allows a malformed HTTP/2 response trailer to crash Envoy, potentially leading to service disruption.
Exploitability: Exploitation requires an attacker to send a specific malformed trailer frame, which is relatively difficult due to the need for precise framing and nghttp2 codec configuration.
Blast radius: If exploited, it could lead to service downtime or crashes affecting cloud-native applications relying on Envoy as a proxy.
Prioritized remediation: Update to Envoy versions 1.36.10, 1.37.6, 1.38.4, or 1.39.1 to mitigate the risk.

proxyhttp2crashservice-disruption

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD 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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

CWE-20, CWE-416

Public exploit & PoC references

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

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