CVE-2026-47207: envoyproxy envoy Use After Free

Vulnerability summary

CVE-2026-47207 is a medium (CVSS 6.5) Use After Free vulnerability in envoyproxy envoy. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 37.5% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 26-06-2026
   PublishedVulnerability first disclosed.
2. 26-06-2026
   Last modifiedVulnerability information updated.

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.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.