Vulnerability-Lookup

GHSA-7JQV-FW35-GMX9

Vulnerability from github – Published: 2026-04-21 17:18 – Updated: 2026-04-21 17:18

Summary

nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding

Details

Summary

When HTMLExporter.embed_images=True, nbconvert's markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML.

Patches

Upgrade to nbconvert 7.17.1

Workarounds

Do not enable HTMLExporter.embed_images (it is not enabled by default).

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "nbconvert"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.5.0"
            },
            {
              "fixed": "7.17.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-39378"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-23"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-21T17:18:53Z",
    "nvd_published_at": "2026-04-21T01:16:06Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nWhen `HTMLExporter.embed_images=True`, nbconvert\u0027s markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML.\n\n## Patches\n\nUpgrade to nbconvert 7.17.1\n\n## Workarounds\n\nDo not enable `HTMLExporter.embed_images` (it is not enabled by default).",
  "id": "GHSA-7jqv-fw35-gmx9",
  "modified": "2026-04-21T17:18:53Z",
  "published": "2026-04-21T17:18:53Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-39378"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jupyter/nbconvert"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyter/nbconvert/releases/tag/v7.17.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding"
}

CVE-2026-39378 (GCVE-0-2026-39378)

Vulnerability from cvelistv5 – Published: 2026-04-21 00:17 – Updated: 2026-04-21 13:43

Title

nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding

Summary

The nbconvert tool, jupyter nbconvert, converts Jupyter notebooks to various other formats via Jinja templates. In versions 6.5 through 7.17.0, when `HTMLExporter.embed_images=True`, nbconvert's markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML. nbconvert 7.17.1 contains a fix. As a workaround, do not enable `HTMLExporter.embed_images`; it is not enabled by default.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

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

References

2 references

URL	Tags
https://github.com/jupyter/nbconvert/security/adv…	x_refsource_CONFIRM
https://github.com/jupyter/nbconvert/releases/tag…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
jupyter	nbconvert	Affected: >= 6.5, < 7.17.1

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-39378",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-21T13:43:09.070985Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-21T13:43:29.081Z",
          "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. In versions 6.5 through 7.17.0, when `HTMLExporter.embed_images=True`, nbconvert\u0027s markdown renderer allows arbitrary file read via path traversal in image references. A malicious notebook can exfiltrate sensitive files from the conversion host by embedding them as base64 data URIs in the output HTML. nbconvert 7.17.1 contains a fix. As a workaround, do not enable `HTMLExporter.embed_images`; it is not enabled by default."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-73",
              "description": "CWE-73: External Control of File Name or Path",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-21T00:17:00.684Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/jupyter/nbconvert/security/advisories/GHSA-7jqv-fw35-gmx9"
        },
        {
          "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-7jqv-fw35-gmx9",
        "discovery": "UNKNOWN"
      },
      "title": "nbconvert has an Arbitrary File Read via Path Traversal in HTMLExporter Image Embedding"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-39378",
    "datePublished": "2026-04-21T00:17:00.684Z",
    "dateReserved": "2026-04-06T21:29:17.350Z",
    "dateUpdated": "2026-04-21T13:43:29.081Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-7JQV-FW35-GMX9

Summary

Patches

Workarounds

CVE-2026-39378 (GCVE-0-2026-39378)

Tags

Sightings

Nomenclature