Vulnerability · Published Jun 26, 2026 · Assigned by GitHub_M

CVE-2026-47207Envoy crashes if multiple unexpected ext_proc responses are packed into one gRPC message

Medium 6.5

In plain English

A medium-severity use-after-free in envoy from envoyproxy. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.4%top 61.2% 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. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, Envoy crashes if an ext_proc server sends a single gRPC message containing multiple, specially crafted ProcessingResponse messages. This can occur when the first response in the batch causes the gRPC stream object to be destroyed, leading to a use-after-free error when Envoy attempts to process subsequent responses in the same gRPC message. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

Affected products (as reported)

Vendor	Product	Versions
envoyproxy	envoy	>= 1.38.0, < 1.38.3>= 1.37.0, < 1.37.5>= 1.36.0, < 1.36.9>= 1.34.0, < 1.35.13

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

References

https://github.com/envoyproxy/envoy/security/advisories/GHSA-68cv-hq5f-g6xv x_refsource_CONFIRM