CVE-2026-25766 (GCVE-0-2026-25766)

Vulnerability from cvelistv5 – Published: 2026-02-19 15:49 – Updated: 2026-02-19 19:46
VLAI
Title
Echo has a Windows path traversal via backslash in middleware.Static default filesystem
Summary
Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo’s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\` as a path separator, so `..\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\` as a path separator and resolves `..\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue.
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: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-02-19 19:45 UTC
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8062 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
labstack echo Affected: >= 5.0.0, < 5.0.3
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-25766",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-19T19:45:33.220477Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-19T19:46:01.829Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "echo",
          "vendor": "labstack",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 5.0.0, \u003c 5.0.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo\u2019s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\\` as a path separator, so `..\\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\\` as a path separator and resolves `..\\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue."
        }
      ],
      "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-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-19T15:49:02.402Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9"
        },
        {
          "name": "https://github.com/labstack/echo/pull/2891",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/labstack/echo/pull/2891"
        },
        {
          "name": "https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1"
        }
      ],
      "source": {
        "advisory": "GHSA-pgvm-wxw2-hrv9",
        "discovery": "UNKNOWN"
      },
      "title": "Echo has a Windows path traversal via backslash in middleware.Static default filesystem"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-25766",
    "datePublished": "2026-02-19T15:49:02.402Z",
    "dateReserved": "2026-02-05T18:35:52.358Z",
    "dateUpdated": "2026-02-19T19:46:01.829Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-25766",
      "date": "2026-11-01",
      "epss": "0.00382",
      "percentile": "0.32308"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "echo",
                "vendor": "labstack",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 5.0.0, \u003c 5.0.3"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:labstack:echo:*:*:*:*:*:go:*:*",
                    "matchCriteriaId": "27FD7D9D-DB8A-4CC1-8024-72E6C1865D46",
                    "versionEndExcluding": "5.0.3",
                    "versionStartIncluding": "5.0.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              },
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*",
                    "matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA",
                    "vulnerable": false
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ],
            "operator": "AND"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo\u2019s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\\` as a path separator, so `..\\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\\` as a path separator and resolves `..\\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue."
          },
          {
            "lang": "es",
            "value": "Echo es un marco web de Go. En las versiones 5.0.0 a 5.0.2 en Windows, el `middleware.Static` de Echo que utiliza el sistema de archivos predeterminado permite recorrer rutas mediante barras invertidas, lo que permite la lectura de archivos remotos no autenticados fuera de la ra\u00edz est\u00e1tica. En `middleware/static.go`, la ruta solicitada no se escapa y se normaliza con `path.Clean` (sem\u00e1ntica de URL). `path.Clean` no trata `\\` como un separador de ruta, por lo que las secuencias `..\\` permanecen en la ruta limpia. La ruta resultante se pasa entonces a `currentFS.Open(...)`. Cuando el sistema de archivos se deja en el valor predeterminado (nil), Echo utiliza `defaultFS`, que llama a `os.Open` (`echo.go:792`). En Windows, `os.Open` trata `\\` como un separador de ruta y resuelve `..\\`, lo que permite el recorrido fuera de la ra\u00edz est\u00e1tica. La versi\u00f3n 5.0.3 corrige el problema."
          }
        ],
        "id": "CVE-2026-25766",
        "lastModified": "2026-06-17T10:25:11.797",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "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"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 1.4,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-25766",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-19T19:45:33.220477Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-02-19T16:27:15.497",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch"
            ],
            "url": "https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Issue Tracking",
              "Patch"
            ],
            "url": "https://github.com/labstack/echo/pull/2891"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Exploit",
              "Vendor Advisory"
            ],
            "url": "https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-22"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2026-02-20T19:40:24+00:00",
      "cve": "CVE-2026-25766",
      "id": "CVE-2026-25766",
      "initial_release_date": "2026-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Echo has a Windows path traversal via backslash in middleware.Static default filesystem",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25766.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-25766",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-02-19T19:45:33.220477Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-02-19T19:45:56.146Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "echo",
              "vendor": "labstack",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003e= 5.0.0, \u003c 5.0.3"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "Echo is a Go web framework. In versions 5.0.0 through 5.0.2 on Windows, Echo\u2019s `middleware.Static` using the default filesystem allows path traversal via backslashes, enabling unauthenticated remote file read outside the static root. In `middleware/static.go`, the requested path is unescaped and normalized with `path.Clean` (URL semantics). `path.Clean` does not treat `\\` as a path separator, so `..\\` sequences remain in the cleaned path. The resulting path is then passed to `currentFS.Open(...)`. When the filesystem is left at the default (nil), Echo uses `defaultFS` which calls `os.Open` (`echo.go:792`). On Windows, `os.Open` treats `\\` as a path separator and resolves `..\\`, allowing traversal outside the static root. Version 5.0.3 fixes the issue."
            }
          ],
          "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-22",
                  "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-02-19T15:49:02.402Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/labstack/echo/security/advisories/GHSA-pgvm-wxw2-hrv9"
            },
            {
              "name": "https://github.com/labstack/echo/pull/2891",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/labstack/echo/pull/2891"
            },
            {
              "name": "https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/labstack/echo/commit/b1d443086ea27cf51345ec72a71e9b7e9d9ce5f1"
            }
          ],
          "source": {
            "advisory": "GHSA-pgvm-wxw2-hrv9",
            "discovery": "UNKNOWN"
          },
          "title": "Echo has a Windows path traversal via backslash in middleware.Static default filesystem"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-25766",
        "datePublished": "2026-02-19T15:49:02.402Z",
        "dateReserved": "2026-02-05T18:35:52.358Z",
        "dateUpdated": "2026-02-19T19:46:01.829Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.