{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.166.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "b82c2939fe9c658de58da993f2798ec5481d7313"
            },
            {
              "fixed": "b50d48c0ebd4761670529bf66f39a9c402a07845"
            }
          ],
          "repo": "https://github.com/node-opcua/node-opcua",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-6wvw-vrw4-363w"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54156.json"
  },
  "details": "node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to 2.166.0, the process-global g_alreadyUsedNonce cache used by nonceAlreadyBeenUsed in packages/node-opcua-secure-channel/source/server/server_secure_channel_layer.ts records nonces from OpenSecureChannelRequest and CreateSession without expiration or a size limit. An unauthenticated remote attacker can repeatedly create sessions with unique nonces, causing entries to persist after session expiry and accumulate across connection cycles even when maxSessions=10 limits concurrent sessions. The resulting unbounded heap growth can exhaust the default Node.js heap and crash the node-opcua server process. This issue is fixed in version 2.166.0.",
  "id": "CVE-2026-54156",
  "modified": "2026-09-16T03:30:44.842403003Z",
  "published": "2026-09-14T16:09:07.744Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/node-opcua/node-opcua/releases/tag/v2.166.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54156.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/node-opcua/node-opcua/security/advisories/GHSA-6wvw-vrw4-363w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54156"
    },
    {
      "type": "FIX",
      "url": "https://github.com/node-opcua/node-opcua/commit/b82c2939fe9c658de58da993f2798ec5481d7313"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "node-opcua: Unbounded nonce cache enables unauthenticated heap exhaustion DoS"
}