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Vulnerability · Published Sep 21, 2026 · Assigned by GitHub_M

CVE-2026-73511Envoy: Potential path-matching/authentication bypass when using Envoy in combination with a backend stripping per-segment path (matrix) parameters (e.g. Apache Tomcat)

Medium 5.3

In plain English

A medium-severity security flaw in envoy from envoyproxy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.4%top 68.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 (as reported)

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

Weakness: CWE-289, CWE-436 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References