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OpenAdvisories
Medium · 5.3 CVE-2026-73511 EUVD-2026-84121

Envoy: Potential path-matching/authentication bypass when using Envoy in combination with a backend stripping per-segment path (matrix) parameters (e.g. Apache Tomcat)

Published Sep 21, 2026 · Updated Sep 22, 2026 · Assigned by GitHub_M

Description

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy normally matches the raw request path, while servlet backends such as Apache Tomcat strip semicolon matrix parameters from each path segment before resolving the resource. Envoy's ignore_path_parameters_in_path_matching option instead truncates at the first semicolon and still does not match per-segment backend behavior. A remote client can use a parameterized protected segment, or a parameter on an earlier segment, to make Envoy select an unprotected fallback while the backend resolves the protected resource. The relevant scope boundary is that the bypass requires both a path-based Envoy decision and a backend that strips semicolon parameters per segment. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

Affected products

VendorProductAffectedFixed
envoyproxy envoy < 1.36.10, >= 1.37.0, < 1.37.6, >= 1.38.0, < 1.38.4, >= 1.39.0, < 1.39.1 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Tumbleweed istioctl 1.30.4-1.1 openSUSE-SU-2026:11630-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 ecs-service-connect-agent v1.39.1.0-1.amzn2023 ALAS2023-2026-2149

Advisories 2

References