CVE-2026-39377 (GCVE-0-2026-39377)

Vulnerability from cvelistv5 – Published: 2026-04-21 00:14 – Updated: 2026-04-21 19:49
VLAI
Title
nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames
Summary
The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. Versions 6.5 through 7.17.0 allow arbitrary file writes to locations outside the intended output directory when processing notebooks containing crafted cell attachment filenames. The `ExtractAttachmentsPreprocessor` passes attachment filenames directly to the filesystem without sanitization, enabling path traversal attacks. This vulnerability provides complete control over both the destination path and file extension. Version 7.17.1 contains a patch.
Severity
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-21 16:01 UTC
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • CWE-73 - External Control of File Name or Path
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 8035 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
jupyter nbconvert Affected: >= 6.5, < 7.17.1
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-39377",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T16:01:22.179013Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T19:49:24.475Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nbconvert",
          "vendor": "jupyter",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 6.5, \u003c 7.17.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. Versions 6.5 through 7.17.0 allow arbitrary file writes to locations outside the intended output directory when processing notebooks containing crafted cell attachment filenames. The `ExtractAttachmentsPreprocessor` passes attachment filenames directly to the filesystem without sanitization, enabling path traversal attacks. This vulnerability provides complete control over both the destination path and file extension. Version 7.17.1 contains a patch."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-73",
              "description": "CWE-73: External Control of File Name or Path",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-21T00:14:59.937Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg"
        },
        {
          "name": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1"
        }
      ],
      "source": {
        "advisory": "GHSA-4c99-qj7h-p3vg",
        "discovery": "UNKNOWN"
      },
      "title": "nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39377",
    "datePublished": "2026-04-21T00:14:59.937Z",
    "dateReserved": "2026-04-06T21:29:17.350Z",
    "dateUpdated": "2026-04-21T19:49:24.475Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-39377",
      "date": "2026-11-01",
      "epss": "0.00266",
      "percentile": "0.18596"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "nbconvert",
                "vendor": "jupyter",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 6.5, \u003c 7.17.1"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:jupyter:nbconvert:*:*:*:*:*:python:*:*",
                    "matchCriteriaId": "B8ACC92D-6ED7-40BE-917E-5527F6746B60",
                    "versionEndExcluding": "7.17.1",
                    "versionStartIncluding": "6.5.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. Versions 6.5 through 7.17.0 allow arbitrary file writes to locations outside the intended output directory when processing notebooks containing crafted cell attachment filenames. The `ExtractAttachmentsPreprocessor` passes attachment filenames directly to the filesystem without sanitization, enabling path traversal attacks. This vulnerability provides complete control over both the destination path and file extension. Version 7.17.1 contains a patch."
          },
          {
            "lang": "es",
            "value": "La herramienta nbconvert, jupyter nbconvert, convierte cuadernos Jupyter a varios otros formatos a trav\u00e9s de plantillas Jinja. Las versiones 6.5 hasta la 7.17.0 permiten escrituras de archivos arbitrarias a ubicaciones fuera del directorio de salida previsto al procesar cuadernos que contienen nombres de archivo de adjuntos de celda manipulados. El \u2019ExtractAttachmentsPreprocessor\u2019 pasa los nombres de archivo de los adjuntos directamente al sistema de archivos sin saneamiento, lo que permite ataques de salto de ruta. Esta vulnerabilidad proporciona control completo tanto sobre la ruta de destino como sobre la extensi\u00f3n del archivo. La versi\u00f3n 7.17.1 contiene un parche."
          }
        ],
        "id": "CVE-2026-39377",
        "lastModified": "2026-10-26T22:10:00.163",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 3.6,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-39377",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T16:01:22.179013Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-04-21T01:16:05.937",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Product"
            ],
            "url": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Mitigation",
              "Vendor Advisory"
            ],
            "url": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-22"
              },
              {
                "lang": "en",
                "value": "CWE-73"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T07:32:23+00:00",
      "cve": "CVE-2026-39377",
      "id": "CVE-2026-39377",
      "initial_release_date": "2026-04-21T00:14:59.937000+00:00",
      "product_status:known_affected": "18",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "nbconvert: nbconvert: Arbitrary file write via crafted Jupyter notebook cell attachment filenames",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39377.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-39377",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-04-21T16:01:22.179013Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-04-21T16:01:26.848Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "nbconvert",
              "vendor": "jupyter",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003e= 6.5, \u003c 7.17.1"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. Versions 6.5 through 7.17.0 allow arbitrary file writes to locations outside the intended output directory when processing notebooks containing crafted cell attachment filenames. The `ExtractAttachmentsPreprocessor` passes attachment filenames directly to the filesystem without sanitization, enabling path traversal attacks. This vulnerability provides complete control over both the destination path and file extension. Version 7.17.1 contains a patch."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 6.5,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-73",
                  "description": "CWE-73: External Control of File Name or Path",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-04-21T00:14:59.937Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-4c99-qj7h-p3vg"
            },
            {
              "name": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1"
            }
          ],
          "source": {
            "advisory": "GHSA-4c99-qj7h-p3vg",
            "discovery": "UNKNOWN"
          },
          "title": "nbconvert has an Arbitrary File Write via Path Traversal in Cell Attachment Filenames"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-39377",
        "datePublished": "2026-04-21T00:14:59.937Z",
        "dateReserved": "2026-04-06T21:29:17.350Z",
        "dateUpdated": "2026-04-21T19:49:24.475Z",
        "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.