{
  "schema_version": "1.4.0",
  "id": "GHSA-whvh-wf3x-g77j",
  "modified": "2026-07-22T23:12:22Z",
  "published": "2026-07-22T23:12:22Z",
  "aliases": [],
  "summary": "JupyterLab: Allowlist/blocklist check in `PyPIExtensionManager.install()` not enforced for direct callers (missing `await`)",
  "details": "The extension allowlist/blocklist check inside `PyPIExtensionManager.install()` was not enforced due to a missing await. For purposes of JupyterLab this was a secondary defense-in-depth check: `install()` was intended to enforce the allowlist/blocklist itself for any future uses and users calling this method directly (in addition to the separate check handling requests arriving through the HTTP API).  The only runtime symptom was a `RuntimeWarning: coroutine 'is_install_allowed' was never awaited.`\n\nThis has security implications only for deployments that combine all of the following:\n- a custom extension or downstream integration that imports `PyPIExtensionManager` and calls `install()` directly with a package name influenced by untrusted user input (the stock JupyterLab HTTP handler is not affected - it performs its own awaited allowlist check before calling `install()`);\n- an allowlist/blocklist configured with the intent of restricting which packages users can install;\n- the (default) PyPI Extension Manager enabled; and\n- kernels and terminals disabled or delegated to remote hosts, so that the custom extension's `install()` call is the only available package-install vector (otherwise a user with kernel access can install packages directly regardless of this check)\n\n### Impact\n\nLow. No exposure for stock JupyterLab: the HTTP API and Extension Manager UI enforce the listing through a separate, correctly awaited check. The gap affected only custom extensions or downstream integrations that called the public `install()` method directly and relied on it to self-enforce.\n\n### Patches\n\nJupyterLab [`v4.6.2`](https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.2) and [`v4.5.10`](https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.10) contain the patch.\n\nUsers of applications that depend on JupyterLab, such as Notebook v7+, should update `jupyterlab` package too.\n\n### Workarounds\n\nNo action is required for deployments that only expose extension management through the JupyterLab HTTP API / Extension Manager UI, as that path was already enforcing the listing via the handler's own check. Deployments wanting to disable programmatic extension installation entirely can switch to the read-only extension manager:\n\n```bash\n--LabApp.extension_manager=readonly\n```\n\nor the following traitlet:\n\n```python\nc.LabApp.extension_manager = 'readonly'\n```\n\nYou can confirm that the read-only manager is in use from GUI:\n\n<img width=\"293\" height=\"293\" alt=\"image\" src=\"https://github.com/user-attachments/assets/8016c809-633e-4ed0-a5bc-6bc4793caa0f\" />",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "jupyterlab"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "4.6.0"
            },
            {
              "fixed": "4.6.2"
            }
          ]
        }
      ],
      "database_specific": {
        "last_known_affected_version_range": "<= 4.6.1"
      }
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "jupyterlab"
      },
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.5.10"
            }
          ]
        }
      ],
      "database_specific": {
        "last_known_affected_version_range": "<= 4.5.9"
      }
    }
  ],
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-whvh-wf3x-g77j"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/pull/19184"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/pull/19185"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/pull/19186"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/commit/be9303f5bcd5308eaeae953c5a3c903046682c2c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/commit/f1beab4a2027af4719d6edc07d52d6cf5a39a432"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/jupyterlab/jupyterlab"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.10"
    },
    {
      "type": "WEB",
      "url": "https://github.com/jupyterlab/jupyterlab/releases/tag/v4.6.2"
    }
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-284",
      "CWE-636"
    ],
    "severity": "LOW",
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-22T23:12:22Z",
    "nvd_published_at": null
  }
}