{"id":"CVE-2026-73551","state":"PUBLISHED","title":"Envoy: Path normalization does not handle dot and dotdot segments with parameters","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.","publishedAt":"2026-09-21T20:17:02.620Z","updatedAt":"2026-09-28T20:41:32.313Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["envoyproxy envoy"],"affected":[{"vendor":"envoyproxy","product":"envoy","versions":[{"version":"< 1.36.10","status":"affected"},{"version":">= 1.37.0, < 1.37.6","status":"affected"},{"version":">= 1.38.0, < 1.38.4","status":"affected"},{"version":">= 1.39.0, < 1.39.1","status":"affected"}]}],"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"],"weaknesses":["CWE-647"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73551.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73551","state":"PUBLISHED","datePublished":"2026-09-21T20:17:02.620Z","dateUpdated":"2026-09-28T20:41:32.313Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-12T20:53:46.380Z"},"containers":{"cna":{"title":"Envoy: Path normalization does not handle dot and dotdot segments with parameters","descriptions":[{"lang":"en","value":"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":[{"vendor":"envoyproxy","product":"envoy","versions":[{"version":"< 1.36.10","status":"affected"},{"version":">= 1.37.0, < 1.37.6","status":"affected"},{"version":">= 1.38.0, < 1.38.4","status":"affected"},{"version":">= 1.39.0, < 1.39.1","status":"affected"}]}],"references":[{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4","name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24","name":"https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b","name":"https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33","name":"https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989","name":"https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","name":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","name":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","name":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":["x_refsource_MISC"]},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","name":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-647","lang":"en","description":"CWE-647: Use of Non-Canonical URL Paths for Authorization Decisions","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-21T20:17:02.620Z"},"source":{"advisory":"GHSA-2w8w-rfw7-8gg4","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-28T20:41:24.834794Z","id":"CVE-2026-73551","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-28T20:41:32.313Z"}}]}}}