CVE-2026-47207
Envoy crashes if multiple unexpected ext_proc responses are packed into one gRPC message
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.
How to fix CVE-2026-47207
To remediate CVE-2026-47207, upgrade the affected package to a fixed version below.
- —upgrade to 1.35.13 or later
Is CVE-2026-47207 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 1.34.0, < 1.35.13, >= 1.36.0, < 1.36.9, >= 1.37.0, < 1.37.5, >= 1.38.0, < 1.38.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |