CVE-2026-27139 (GCVE-0-2026-27139)

Vulnerability from cvelistv5 – Published: 2026-03-06 21:28 – Updated: 2026-03-09 14:53
VLAI
Title
FileInfo can escape from a Root in os
Summary
On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root.
Severity
2.5 (Low)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-09 14:53 UTC
CWE
  • CWE-363 - Race Condition Enabling Link Following
Assigner
Go CNA under the Google root
CNA scorecard E 42/100 over 76 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Go standard library os Affected: 0 , < 1.25.8 (semver)
Affected: 1.26.0-0 , < 1.26.1 (semver)
guessed Create a notification for this product.
Credits
Miloslav Trmač of Red Hat
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "NONE",
              "baseScore": 2.5,
              "baseSeverity": "LOW",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-27139",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-09T14:53:55.467850Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-09T14:53:58.363Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "os",
          "product": "os",
          "programRoutines": [
            {
              "name": "File.ReadDir"
            },
            {
              "name": "File.Readdir"
            },
            {
              "name": "ReadDir"
            },
            {
              "name": "dirFS.ReadDir"
            },
            {
              "name": "rootFS.ReadDir"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.8",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.1",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Miloslav Trma\u010d of Red Hat"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-363: Race Condition Enabling Link Following",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-06T21:28:14.451Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk"
        },
        {
          "url": "https://go.dev/issue/77827"
        },
        {
          "url": "https://go.dev/cl/749480"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4602"
        }
      ],
      "title": "FileInfo can escape from a Root in os"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-27139",
    "datePublished": "2026-03-06T21:28:14.451Z",
    "dateReserved": "2026-02-17T19:57:28.435Z",
    "dateUpdated": "2026-03-09T14:53:58.363Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-27139",
      "date": "2026-11-15",
      "epss": "0.00219",
      "percentile": "0.12523"
    },
    "microsoft_vex": {
      "current_release_date": "2026-04-15T01:40:46.000Z",
      "cve": "CVE-2026-27139",
      "id": "msrc_CVE-2026-27139",
      "initial_release_date": "2026-03-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "3",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "FileInfo can escape from a Root in os",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-27139.json",
      "version": "4"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://pkg.go.dev",
                "defaultStatus": "unaffected",
                "packageName": "os",
                "product": "os",
                "programRoutines": [
                  {
                    "name": "File.ReadDir"
                  },
                  {
                    "name": "File.Readdir"
                  },
                  {
                    "name": "ReadDir"
                  },
                  {
                    "name": "dirFS.ReadDir"
                  },
                  {
                    "name": "rootFS.ReadDir"
                  }
                ],
                "vendor": "Go standard library",
                "versions": [
                  {
                    "lessThan": "1.25.8",
                    "status": "affected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "1.26.1",
                    "status": "affected",
                    "version": "1.26.0-0",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "security@golang.org"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "2D293CC0-B163-4E62-B985-52FB6ECA64C5",
                    "versionEndExcluding": "1.25.8",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "A40FE3CB-0D03-462B-8A19-4DF1920ABE82",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root."
          },
          {
            "lang": "es",
            "value": "En plataformas Unix, al listar el contenido de un directorio usando File.ReadDir o File.Readdir, el FileInfo devuelto podr\u00eda hacer referencia a un archivo fuera de la Ra\u00edz en la que se abri\u00f3 el Archivo. El impacto de este escape se limita a la lectura de metadatos proporcionados por lstat desde ubicaciones arbitrarias en el sistema de archivos sin permitir la lectura o escritura de archivos fuera de la ra\u00edz."
          }
        ],
        "id": "CVE-2026-27139",
        "lastModified": "2026-06-17T10:26:44.230",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "NONE",
                "baseScore": 2.5,
                "baseSeverity": "LOW",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.0,
              "impactScore": 1.4,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-27139",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-09T14:53:55.467850Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-03-06T22:16:01.070",
        "references": [
          {
            "source": "security@golang.org",
            "tags": [
              "Mailing List"
            ],
            "url": "https://go.dev/cl/749480"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Issue Tracking"
            ],
            "url": "https://go.dev/issue/77827"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Release Notes"
            ],
            "url": "https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk"
          },
          {
            "source": "security@golang.org",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://pkg.go.dev/vuln/GO-2026-4602"
          }
        ],
        "sourceIdentifier": "security@golang.org",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-22"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-11-07T10:40:02+00:00",
      "cve": "CVE-2026-27139",
      "id": "CVE-2026-27139",
      "initial_release_date": "2026-03-06T21:28:14.451000+00:00",
      "product_status:fixed": "32",
      "product_status:known_affected": "24",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "os: FileInfo can escape from a Root in golang os module",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27139.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "HIGH",
                  "attackVector": "LOCAL",
                  "availabilityImpact": "NONE",
                  "baseScore": 2.5,
                  "baseSeverity": "LOW",
                  "confidentialityImpact": "LOW",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "LOW",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-27139",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-03-09T14:53:55.467850Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-03-09T14:53:42.735Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "collectionURL": "https://pkg.go.dev",
              "defaultStatus": "unaffected",
              "packageName": "os",
              "product": "os",
              "programRoutines": [
                {
                  "name": "File.ReadDir"
                },
                {
                  "name": "File.Readdir"
                },
                {
                  "name": "ReadDir"
                },
                {
                  "name": "dirFS.ReadDir"
                },
                {
                  "name": "rootFS.ReadDir"
                }
              ],
              "vendor": "Go standard library",
              "versions": [
                {
                  "lessThan": "1.25.8",
                  "status": "affected",
                  "version": "0",
                  "versionType": "semver"
                },
                {
                  "lessThan": "1.26.1",
                  "status": "affected",
                  "version": "1.26.0-0",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "value": "Miloslav Trma\u010d of Red Hat"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "description": "CWE-363: Race Condition Enabling Link Following",
                  "lang": "en"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-03-06T21:28:14.451Z",
            "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
            "shortName": "Go"
          },
          "references": [
            {
              "url": "https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk"
            },
            {
              "url": "https://go.dev/issue/77827"
            },
            {
              "url": "https://go.dev/cl/749480"
            },
            {
              "url": "https://pkg.go.dev/vuln/GO-2026-4602"
            }
          ],
          "title": "FileInfo can escape from a Root in os"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "assignerShortName": "Go",
        "cveId": "CVE-2026-27139",
        "datePublished": "2026-03-06T21:28:14.451Z",
        "dateReserved": "2026-02-17T19:57:28.435Z",
        "dateUpdated": "2026-03-09T14:53:58.363Z",
        "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
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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.