CVE-2026-73551 (GCVE-0-2026-73551)

Vulnerability from cvelistv5 – Published: 2026-09-21 20:17 – Updated: 2026-09-28 20:41
VLAI
Title
Envoy: Path normalization does not handle dot and dotdot segments with parameters
Summary
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.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-28 20:41 UTC
CWE
  • CWE-647 - Use of Non-Canonical URL Paths for Authorization Decisions
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7634 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
envoyproxy envoy Affected: < 1.36.10
Affected: >= 1.37.0, < 1.37.6
Affected: >= 1.38.0, < 1.38.4
Affected: >= 1.39.0, < 1.39.1
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                "x_refsource_MISC"
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              "url": "https://github.com/envoyproxy/envoy/releases/tag/v1.39.1"
            }
          ],
          "source": {
            "advisory": "GHSA-2w8w-rfw7-8gg4",
            "discovery": "UNKNOWN"
          },
          "title": "Envoy: Path normalization does not handle dot and dotdot segments with parameters"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-73551",
        "datePublished": "2026-09-21T20:17:02.620Z",
        "dateReserved": "2026-08-12T20:53:46.380Z",
        "dateUpdated": "2026-09-28T20:41:32.313Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Sightings

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