# CVE-2026-73551: Envoy: Path normalization does not handle dot and dotdot segments with parameters

> CVE-2026-73551: Envoy: Path normalization does not handle dot and dotdot segments with parameters. CVSS 5.3 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-73551
Last updated: 2026-10-05T14:06:32Z

- Published: 2026-09-21 20:17 UTC · Updated: 2026-10-05 14:06 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: 0.53%, 44th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-647

## 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's URL normalization does not recognize dot and dotdot path segments when they carry semicolon parameters. A request such as /user/..;foo=bar/admin is therefore not canonicalized to /admin even when path normalization is enabled. If an upstream interprets the segment according to RFC 3986 while Envoy applies routing or RBAC to the uncollapsed path, a remote client can cause path confusion and bypass path-based security policy. The relevant scope boundary is that the security consequence depends on a downstream/upstream path interpretation mismatch or a path-based Envoy decision. 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-2026-73551)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-73551)
- [https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24](https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24)
- [https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b](https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b)
- [https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33](https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33)
- [https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989](https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989)
- [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-2w8w-rfw7-8gg4](https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4)

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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-2026-73551 · Markdown: https://rewindex.com/cve/CVE-2026-73551.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-73551 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:39.510Z