CVE-2026-54156

High

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.

SeverityHigh
CVSS7.5
Exploit probability—
ProductNode-opcua
PublishedSep 14, 2026
First seenSep 14, 2026

How to fix

Update
  • node-opcua2.166.0 or later

Affected products

ProductAffected versionsFixed in
node-opcuanpmv < 2.166.02.166.0

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