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

> CVE-2026-73511: Envoy: Potential path-matching/authentication bypass when using Envoy in combination with a backend stripping per-segment path (matrix) parameters (e.g. Apache Tomcat). CVSS 5.3 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-73511
Last updated: 2026-10-05T14:35:20Z

- Published: 2026-09-21 20:20 UTC · Updated: 2026-10-05 14:35 UTC · Assigner: GitHub\_M
- CVSS: 5.3 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS: 0.38%, 31th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-289, CWE-436

## 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 vendors and products

- envoyproxy: envoy

## Tracked companies

- [Google Cloud](https://rewindex.com/company/google-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-73511)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-73511)
- [https://github.com/envoyproxy/envoy/commit/26d5](https://github.com/envoyproxy/envoy/commit/26d5)
- [https://github.com/envoyproxy/envoy/commit/50f7bfa48dccfee339822e9846b2b8053e07d325](https://github.com/envoyproxy/envoy/commit/50f7bfa48dccfee339822e9846b2b8053e07d325)
- [https://github.com/envoyproxy/envoy/commit/b205d1f4982e14ce5693ba94ef84d37e7155e050](https://github.com/envoyproxy/envoy/commit/b205d1f4982e14ce5693ba94ef84d37e7155e050)
- [https://github.com/envoyproxy/envoy/commit/fcb663752c7055257f5dcc8b6ce6c7c905ebb1ff](https://github.com/envoyproxy/envoy/commit/fcb663752c7055257f5dcc8b6ce6c7c905ebb1ff)
- [https://github.com/envoyproxy/envoy/releases/tag/v1.36.10](https://github.com/envoyproxy/envoy/releases/tag/v1.36.10)
- [https://github.com/envoyproxy/envoy/releases/tag/v1.37.6](https://github.com/envoyproxy/envoy/releases/tag/v1.37.6)
- [https://github.com/envoyproxy/envoy/releases/tag/v1.38.4](https://github.com/envoyproxy/envoy/releases/tag/v1.38.4)
- [https://github.com/envoyproxy/envoy/releases/tag/v1.39.1](https://github.com/envoyproxy/envoy/releases/tag/v1.39.1)
- [https://github.com/envoyproxy/envoy/security/advisories/GHSA-m745-gh6x-349x](https://github.com/envoyproxy/envoy/security/advisories/GHSA-m745-gh6x-349x)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-73511 · Markdown: https://rewindex.com/cve/CVE-2026-73511.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-73511 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:45.980Z