GHSA-9F66-54XG-PC2C

Vulnerability from github – Published: 2020-12-21 18:01 – Updated: 2026-05-19 20:24
VLAI
Summary
Jupyter Server open redirect vulnerability
Details

Impact

What kind of vulnerability is it? Who is impacted?

Open redirect vulnerability - a maliciously crafted link to a jupyter server could redirect the browser to a different website.

All jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may appear safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8.

Patches

Has the problem been patched? What versions should users upgrade to?

Patched in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix:

jupyter server --ServerApp.base_url=/jupyter/

References

OWASP page on open redirects

For more information

If you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list security@ipython.org.

Credit: Yaniv Nizry from CxSCA group at Checkmarx

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "jupyter-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-26275"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-12-21T18:00:51Z",
    "nvd_published_at": "2020-12-21T18:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\nOpen redirect vulnerability - a maliciously crafted link to a jupyter server could redirect the browser to a different website.\n\nAll jupyter servers running without a base_url prefix are technically affected, however, these maliciously crafted links can only be reasonably made for known jupyter server hosts. A link to your jupyter server may *appear* safe, but ultimately redirect to a spoofed server on the public internet. This same vulnerability was patched in upstream notebook v5.7.8.\n\n### Patches\n\n_Has the problem been patched? What versions should users upgrade to?_\n\nPatched in jupyter_server 1.1.1. If upgrade is not available, a workaround can be to run your server on a url prefix:\n\n```\njupyter server --ServerApp.base_url=/jupyter/\n```\n\n### References\n\n[OWASP page on open redirects](https://cheatsheetseries.owasp.org/cheatsheets/Unvalidated_Redirects_and_Forwards_Cheat_Sheet.html)\n\n### For more information\n\nIf you have any questions or comments about this advisory, or vulnerabilities to report, please email our security list [security@ipython.org](mailto:security@ipython.org).\n\nCredit: Yaniv Nizry from CxSCA group at Checkmarx",
  "id": "GHSA-9f66-54xg-pc2c",
  "modified": "2026-05-19T20:24:16Z",
  "published": "2020-12-21T18:01:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jupyter-server/jupyter_server/security/advisories/GHSA-9f66-54xg-pc2c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-26275"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyter-server/jupyter_server/commit/85e4abccf6ea9321d29153f73b0bd72ccb3a6bca"
    },
    {
      "type": "WEB",
      "url": "https://advisory.checkmarx.net/advisory/CX-2020-4291"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jupyter-server/jupyter_server"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-346.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/jupyter-server/PYSEC-2020-50.yaml"
    },
    {
      "type": "WEB",
      "url": "https://pypi.org/project/jupyter-server"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Jupyter Server open redirect vulnerability"
}



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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.



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