CVE-2026-21636 (GCVE-0-2026-21636)

Vulnerability from cvelistv5 – Published: 2026-01-20 20:41 – Updated: 2026-01-21 18:52
VLAI
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.
Severity
5.8 (Medium)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-284 - Improper Access Control
Assigner
References
Impacted products
Vendor Product Version
nodejs node Affected: 25.2.1 , ≤ 25.2.1 (semver)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-21636",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-21T18:38:13.137061Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-284",
                "description": "CWE-284 Improper Access Control",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-21T18:52:53.133Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "node",
          "vendor": "nodejs",
          "versions": [
            {
              "lessThanOrEqual": "25.2.1",
              "status": "affected",
              "version": "25.2.1",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw in Node.js\u0027s 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.\n\n* The issue affects users of the Node.js permission model on version v25.\n\nIn the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase."
        }
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "baseScore": 5.8,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N",
            "version": "3.0"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-20T20:41:55.700Z",
        "orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1",
        "shortName": "hackerone"
      },
      "references": [
        {
          "url": "https://nodejs.org/en/blog/vulnerability/december-2025-security-releases"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1",
    "assignerShortName": "hackerone",
    "cveId": "CVE-2026-21636",
    "datePublished": "2026-01-20T20:41:55.700Z",
    "dateReserved": "2026-01-01T15:00:02.339Z",
    "dateUpdated": "2026-01-21T18:52:53.133Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-21636",
      "date": "2026-06-18",
      "epss": "0.00663",
      "percentile": "0.46835"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-21636\",\"sourceIdentifier\":\"support@hackerone.com\",\"published\":\"2026-01-20T21:16:05.813\",\"lastModified\":\"2026-01-30T20:20:56.843\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"A flaw in Node.js\u0027s 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.\\n\\n* The issue affects users of the Node.js permission model on version v25.\\n\\nIn the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H\",\"baseScore\":10.0,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":6.0}],\"cvssMetricV30\":[{\"source\":\"support@hackerone.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.0\",\"vectorString\":\"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N\",\"baseScore\":5.8,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":1.4}]},\"weaknesses\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-284\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*\",\"versionStartIncluding\":\"25.0.0\",\"versionEndExcluding\":\"25.3.0\",\"matchCriteriaId\":\"970EF154-D905-4FDA-85CB-C3AB08BEFAEC\"}]}]}],\"references\":[{\"url\":\"https://nodejs.org/en/blog/vulnerability/december-2025-security-releases\",\"source\":\"support@hackerone.com\",\"tags\":[\"Vendor Advisory\",\"Release Notes\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-21636\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-01-21T18:38:13.137061Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-284\", \"description\": \"CWE-284 Improper Access Control\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-01-21T18:40:15.504Z\"}}], \"cna\": {\"metrics\": [{\"cvssV3_0\": {\"version\": \"3.0\", \"baseScore\": 5.8, \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N\"}}], \"affected\": [{\"vendor\": \"nodejs\", \"product\": \"node\", \"versions\": [{\"status\": \"affected\", \"version\": \"25.2.1\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"25.2.1\"}], \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://nodejs.org/en/blog/vulnerability/december-2025-security-releases\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"A flaw in Node.js\u0027s 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.\\n\\n* The issue affects users of the Node.js permission model on version v25.\\n\\nIn the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.\"}], \"providerMetadata\": {\"orgId\": \"36234546-b8fa-4601-9d6f-f4e334aa8ea1\", \"shortName\": \"hackerone\", \"dateUpdated\": \"2026-01-20T20:41:55.700Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-21636\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-01-21T18:52:53.133Z\", \"dateReserved\": \"2026-01-01T15:00:02.339Z\", \"assignerOrgId\": \"36234546-b8fa-4601-9d6f-f4e334aa8ea1\", \"datePublished\": \"2026-01-20T20:41:55.700Z\", \"assignerShortName\": \"hackerone\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.