CVE-2026-73551
Envoy: Path normalization does not handle dot and dotdot segments with parameters
- State
- Published
- Severity
- 5.3 Medium
- Published
- Sep 21, 2026
- Updated
- Sep 28, 2026
- Reserved
- Aug 12, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | GitHub_M |
Weaknesses
- CWE-647 Use of Non-Canonical URL Paths for Authorization Decisions
Affected Products
| Product | Versions |
|---|---|
envoyenvoyproxy |
|
References
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4
- https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24
- https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b
- https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33
- https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989
- https://github.com/envoyproxy/envoy/releases/tag/v1.36.10
- https://github.com/envoyproxy/envoy/releases/tag/v1.37.6
- https://github.com/envoyproxy/envoy/releases/tag/v1.38.4
- https://github.com/envoyproxy/envoy/releases/tag/v1.39.1
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