CVE-2026-47207: Envoy crashes if multiple unexpected ext_proc responses are packed into one gRPC message
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 extproc 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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.35.13 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.36.9 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.37.5 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.38.3
Event History
Frequently Asked Questions
What is the severity of CVE-2026-47207?
The severity of CVE-2026-47207 is medium with a CVSS score of 6.5.
How does CVE-2026-47207 affect Envoy?
CVE-2026-47207 causes Envoy to crash when multiple unexpected ext_proc responses are packed into a single gRPC message.
Which versions of Envoy are impacted by CVE-2026-47207?
CVE-2026-47207 affects Envoy versions from 1.34.0 to 1.35.13, 1.36.9, 1.37.5, and 1.38.3.
How can I mitigate CVE-2026-47207?
To mitigate CVE-2026-47207, upgrade Envoy to a version that is not affected, specifically any version after 1.38.3.
What kind of attack does CVE-2026-47207 represent?
CVE-2026-47207 represents a denial-of-service vulnerability that could lead to crashes in Envoy.