Security advisory

{
  "id": "c57f246ece9b84aea93d563523c87efa66e7906e2ab598ef67e5a693ce7da51c",
  "url": "https://osv.dev/vulnerability/CVE-2026-21636",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-21636",
    "summary": "A flaw in Node.js's permission model allows Unix Domain Socket (UDS) connections to bypass network restrictions when `--permission` is enabled. Even without `--allow-net`, attacker-controlled inputs (such as URLs or socketPath options) can connect to arbitrary local sockets via net, tls, or undici/fetch. This breaks the intended security boundary of the permission model and enables access to privileged local services, potentially leading to privilege escalation, data exposure, or local code execution. * The issue affects users of the Node.js permission model on version v25. In the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.",
    "evidence": "osv:CVE-2026-21636",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-21636",
      "aliases": [
        "BIT-node-2026-21636",
        "BIT-node-min-2026-21636",
        "CVE-2026-21636"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nodejs/node",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0b3a10d4c8ba5e15429287e725d22615be896e95"
                },
                {
                  "fixed": "00d6cd83927d6d5c8fe9d0cdd101daa6df4b1a15"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "25.0.0"
                      },
                      {
                        "fixed": "25.3.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v25.2.1",
            "v25.2.0",
            "v25.1.0",
            "v25.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21636.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.234551484Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21636.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-21636",
        "https://nodejs.org/en/blog/vulnerability/december-2025-security-releases"
      ],
      "provider_metadata": {
        "cna_assigner": "hackerone",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "25.2.1"
                  },
                  {
                    "last_affected": "25.2.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandaloneSingleVersion"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21636.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-21636",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 513381,
  "published_at": "2026-01-20T20:41:55.7+00:00"
}