JupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped Hyphen

{
  "id": "32e6f096f52e1d969cfbe6e8ddf64da8d435f5cb4380fa55a40ee1e192900f34",
  "url": "https://osv.dev/vulnerability/CVE-2026-108752",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "JupyterHub through 6.0.1 OAuth Client ID Collision via Unescaped Hyphen",
    "summary": "JupyterHub through 6.0.1 contains an identifier collision vulnerability that allows authenticated users to overwrite another user's named-server OAuth client by registering a hyphenated username. Attackers holding a name like alice-prod can overwrite the client for alice's server prod, breaking OAuth login and revoking tokens by stopping their own server.",
    "evidence": "osv:CVE-2026-108752",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-108752",
      "aliases": [
        "BIT-jupyterhub-2026-108752",
        "CVE-2026-108752"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/jupyterhub/jupyterhub",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "3e516c6f382b481e815ec455befb2f14d80d337b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "6.0.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "6.0.1"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "6.0.1",
            "6.0.0",
            "6.0.0b3",
            "6.0.0b2",
            "6.0.0b1",
            "5.4.2",
            "5.4.1",
            "5.4.0",
            "5.3.0",
            "5.3.0rc0",
            "5.2.1",
            "5.2.0",
            "5.1.0",
            "5.0.0",
            "5.0.0b2",
            "5.0.0b1",
            "4.0.1",
            "4.0.0",
            "4.0.0b2",
            "4.0.0b1",
            "3.1.0",
            "3.0.0",
            "3.0.0b1",
            "2.2.2",
            "2.2.1",
            "2.2.0",
            "2.1.1",
            "2.1.0",
            "2.0.2",
            "2.0.1",
            "2.0.0",
            "2.0.0rc5",
            "2.0.0rc4",
            "2.0.0rc3",
            "2.0.0rc2",
            "2.0.0rc1",
            "2.0.0b3",
            "2.0.0b2",
            "2.0.0b1",
            "1.4.0",
            "1.3.0",
            "1.2.1",
            "1.0.0",
            "1.2.0",
            "1.2.0b1",
            "1.1.0",
            "1.1.0b1",
            "1.0.0b2",
            "1.0.0b1",
            "0.9.2",
            "0.9.1",
            "0.9.0",
            "0.9.0rc1",
            "0.9.0b3",
            "0.9.0b2",
            "0.9.0b1",
            "0.8.1",
            "0.8.0",
            "0.8.0rc2",
            "0.8.0rc1",
            "0.8.0b5",
            "0.8.0b4",
            "0.8.0b3",
            "0.8.0b2",
            "0.8.0b1",
            "0.7.2",
            "0.7.1",
            "0.7.0",
            "0.6.1",
            "0.6.0",
            "0.5.0",
            "0.4.1",
            "0.4.0",
            "0.3.0",
            "0.2.0",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-108752.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:41.239001337Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/108xxx/CVE-2026-108752.json",
        "https://hackmd.io/@haind/jupyterhub-oauth-client-id-cross-user-collision",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-108752",
        "https://www.vulncheck.com/advisories/jupyterhub-through-6.0.1-oauth-client-id-collision-via-unescaped-hyphen",
        "https://github.com/jupyterhub/jupyterhub",
        "https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/oauth/provider.py#L719-L754",
        "https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L1174-L1186",
        "https://github.com/jupyterhub/jupyterhub/blob/3e516c6f382b481e815ec455befb2f14d80d337b/jupyterhub/user.py#L563-L567"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-694"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/108xxx/CVE-2026-108752.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-108752",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509131,
  "published_at": "2026-10-11T12:19:51.996+00:00"
}