CVE-2023-35943: Envoyproxy Envoy

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, the CORS filter will segfault and crash Envoy when the `origin` header is removed and deleted between `decodeHeaders`and `encodeHeaders`. Versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12 have a fix for this issue. As a workaround, do not remove the `origin` header in the Envoy configuration.

Affected products

• Envoyproxy Envoy: from 1.23.0, before 1.23.12 (fixed in 1.23.12); from 1.24.0, before 1.24.10 (fixed in 1.24.10); from 1.25.0, before 1.25.9 (fixed in 1.25.9); from 1.26.0, before 1.26.4 (fixed in 1.26.4)

Published 2023-07-25. Last modified 2026-06-17.