{"id":"CVE-2026-73551","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-73551","generatedAt":"2026-10-28T02:22:14.057Z","title":"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.","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.","published":"2026-09-21T21:17:09.000Z","lastModified":"2026-10-05T14:06:32.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-647"],"affected":["envoyproxy/envoy"],"epss":{"score":0.00527,"percentile":0.44342,"date":"2026-10-26","history":[{"date":"2026-09-22","score":0.00554,"percentile":0.45121}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.53%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-21T21:17:09.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-09-21T21:17:09.473Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.36.10","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.37.6","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.38.4","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/releases/tag/v1.39.1","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4","tags":["Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-73551","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}