{"id":"CVE-2026-73551","published":"2026-09-21T21:17:09.473","lastModified":"2026-09-21T21:17:09.473","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.","cvssScore":5.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cwes":["CWE-647"],"vendors":[],"products":[],"references":[{"url":"https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4","tags":[]}],"exploitRefs":[{"url":"https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33","tags":[]},{"url":"https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":[]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":[]},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4","tags":[]}],"hasPoc":true,"ai":{"summary":"The flaw allows path confusion by not properly normalizing URL segments with semicolons, potentially bypassing security policies.","exploitability":"Exploitation requires specific URL formatting and a misalignment in how upstream and Envoy interpret paths; moderately difficult.","blast_radius":"If exploited, could lead to unauthorized access or policy bypass affecting cloud-native applications using Envoy as a proxy.","remediation":"Update to Envoy versions 1.36.10, 1.37.6, 1.38.4, or 1.39.1 to mitigate the vulnerability.","tags":["path-confusion","security-policy-bypass","cloud-native","proxy"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-22T06:28:48.816Z"}}