{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54156","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-11T21:15:33.872Z","datePublished":"2026-09-14T16:09:07.744Z","dateUpdated":"2026-09-14T16:35:48.958Z"},"containers":{"cna":{"title":"node-opcua: Unbounded nonce cache enables unauthenticated heap exhaustion DoS","problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"name":"https://github.com/node-opcua/node-opcua/security/advisories/GHSA-6wvw-vrw4-363w","tags":["x_refsource_CONFIRM"],"url":"https://github.com/node-opcua/node-opcua/security/advisories/GHSA-6wvw-vrw4-363w"},{"name":"https://github.com/node-opcua/node-opcua/commit/b82c2939fe9c658de58da993f2798ec5481d7313","tags":["x_refsource_MISC"],"url":"https://github.com/node-opcua/node-opcua/commit/b82c2939fe9c658de58da993f2798ec5481d7313"},{"name":"https://github.com/node-opcua/node-opcua/releases/tag/v2.166.0","tags":["x_refsource_MISC"],"url":"https://github.com/node-opcua/node-opcua/releases/tag/v2.166.0"}],"affected":[{"vendor":"node-opcua","product":"node-opcua","versions":[{"version":"< 2.166.0","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-09-14T16:09:07.744Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-6wvw-vrw4-363w","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-14T16:35:36.222019Z","id":"CVE-2026-54156","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-14T16:35:48.958Z"}}]}}