CVE-2026-73513 Envoy: oghttp2 upstream trailers incorrect handling
A use-after-free vulnerability in Envoy's optional oghttp2 codec allows remote attackers to crash the proxy via malformed HTTP/2 trailers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-73513?
CVE-2026-73513 is a high-severity use after free vulnerability in Envoyproxy Envoy, published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Which versions are affected by CVE-2026-73513?
1 open source package ship an affected version, including envoy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
envoy Bitnami | All versions | 1.36.10, 1.37.6, 1.38.4, 1.39.1 |
Products include Envoyproxy Envoy.
How do I fix CVE-2026-73513?
Upgrade envoy to a fixed version for your release line: 1.36.10, 1.37.6, 1.38.4 or 1.39.1.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-73513 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73513 exists.
Other vulnerabilities in Envoyproxy Envoy
Sources
Also known as BIT-envoy-2026-73513, GHSA-jjmm-fw8p-crpw, MINI-44wm-fh3g-v3c2, MINI-8fwr-r5q2-pr35, MINI-cxm4-j45m-jr5q, MINI-rf98-pvhq-qg8x.