{"cve":"CVE-2026-54156","nvd":{"published":"2026-09-14T17:17:46.927","modified":"2026-09-30T19:38:27.293","status":"Awaiting Analysis","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://github.com/node-opcua/node-opcua/commit/b82c2939fe9c658de58da993f2798ec5481d7313","https://github.com/node-opcua/node-opcua/releases/tag/v2.166.0","https://github.com/node-opcua/node-opcua/security/advisories/GHSA-6wvw-vrw4-363w"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-54156","score":0.00784,"percentile":0.55772,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-6wvw-vrw4-363w","url":"https://osv.dev/vulnerability/GHSA-6wvw-vrw4-363w","summary":"node-opcua: Unbounded nonce cache enables unauthenticated heap exhaustion DoS","modified":"2026-08-27T19:15:07.090081514Z","packages":[{"ecosystem":"npm","name":"node-opcua","purl":"pkg:npm/node-opcua","ranges":["<2.166.0"],"fixed":["2.166.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}