Security advisory

{
  "id": "0d079829383c28ebb140fc8d63e4651f563c72123a81494f4ef7ca34d3016ede",
  "url": "https://osv.dev/vulnerability/CVE-2020-26261",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-26261",
    "summary": "jupyterhub-systemdspawner enables JupyterHub to spawn single-user notebook servers using systemd. In jupyterhub-systemdspawner before version 0.15 user API tokens issued to single-user servers are specified in the environment of systemd units. These tokens are incorrectly accessible to all users. In particular, the-littlest-jupyterhub is affected, which uses systemdspawner by default. This is patched in jupyterhub-systemdspawner v0.15",
    "evidence": "osv:CVE-2020-26261",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-26261",
      "aliases": [
        "CVE-2020-26261",
        "GHSA-cg54-gpgr-4rm6",
        "PYSEC-2020-52"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/jupyterhub/systemdspawner",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7d7cf42db76d9cfa5a4bc42fff14943877ac570b"
                },
                {
                  "fixed": "a4d08fd2ade1cfd0ef2c29dc221e649345f23580"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:jupyterhub:systemdspawner:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.15"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "a4d08fd2ade1cfd0ef2c29dc221e649345f23580"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.14.0",
            "v0.13",
            "v0.11",
            "v0.10",
            "v0.9.9",
            "0.9.7",
            "v0.9.6",
            "v0.9.5"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26261.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:56.586518809Z",
      "provider": "osv",
      "references": [
        "https://github.com/jupyterhub/systemdspawner/blob/master/CHANGELOG.md#v015",
        "https://github.com/jupyterhub/systemdspawner/security/advisories/GHSA-cg54-gpgr-4rm6",
        "https://github.com/jupyterhub/systemdspawner/commit/a4d08fd2ade1cfd0ef2c29dc221e649345f23580",
        "https://pypi.org/project/jupyterhub-systemdspawner/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-26261",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 384071,
  "published_at": "2020-12-09T17:15:30.603+00:00"
}