CVE-2026-73551
published 2026-09-21CVE-2026-73551: 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…
PriorityP433medium5.3CVSS 3.1
AVNACLPRNUINSUCLINAN
EPSS
0.53%
43.8th percentile
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
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| envoyproxy | envoy | < 1.36.10 | 1.36.10 |
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | — | — |
| envoyproxy | envoy | >= 1.37.0 < 1.37.6 | 1.37.6 |
| envoyproxy | envoy | >= 1.38.0 < 1.38.4 | 1.38.4 |
| envoyproxy | envoy | >= 1.39.0 < 1.39.1 | 1.39.1 |
| openshift-service-mesh | istio-proxyv2-rhel9 | — | — |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
vendor_redhat5.3MEDIUM
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VulDB
EnvoyProxy Envoy up to 1.36.9/1.37.5/1.38.3/1.39.0 URL Normalization access control
vuldb·2026-09-21·CVSS 5.3
CVE-2026-73551 [MEDIUM] EnvoyProxy Envoy up to 1.36.9/1.37.5/1.38.3/1.39.0 URL Normalization access control
A vulnerability classified as problematic was found in EnvoyProxy Envoy up to 1.36.9/1.37.5/1.38.3/1.39.0. Affected by this vulnerability is an unknown functionality of the component URL Normalization. Such manipulation leads to improper access controls.
This vulnerability is traded as CVE-2026-73551. The attack may be launched remotely. There is no exploit available.
Upgrading the affected component is advised.
Red Hat
envoy: envoy: path normalization bypass via dot/dot-dot segments with parameters
vendor_redhat·2026-08-26·CVSS 5.3
CVE-2026-73551 [MEDIUM] CWE-22 envoy: envoy: path normalization bypass via dot/dot-dot segments with parameters
envoy: envoy: path normalization bypass via dot/dot-dot segments with parameters
No description is available for this CVE.
Package: openshift-service-mesh/istio-proxyv2-rhel9 (OpenShift Service Mesh 3) - Affected
No detection rules found.
No public exploits indexed.
https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37bhttps://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989https://github.com/envoyproxy/envoy/releases/tag/v1.36.10https://github.com/envoyproxy/envoy/releases/tag/v1.37.6https://github.com/envoyproxy/envoy/releases/tag/v1.38.4https://github.com/envoyproxy/envoy/releases/tag/v1.39.1https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4
2026-09-21
Published