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TI-2026-39066 Aliases CVE-2026-54156GHSA-6wvw-vrw4-363w

node-opcua: Unbounded nonce cache enables unauthenticated heap exhaustion DoS

Priority MEDIUM 40CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-770.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00784 56th percentileScored 2026-11-07
Fix Fixed node-opcua (node-opcua): 2.166.0node-opcua (npm): 2.166.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
node-opcuanode-opcuabefore 2.166.02.166.0Patch availableCNA
—node-opcua (npm)before 2.166.02.166.0Patch availableGHSA-6wvw-vrw4-363w
  • node-opcua Vendornode-opcua Affected before 2.166.0 Fixed in 2.166.0 Patch available CNA
  • node-opcua (npm) Vendor— Affected before 2.166.0 Fixed in 2.166.0 Patch available GHSA-6wvw-vrw4-363w

Remediation

  • Fix · CNA node-opcua (node-opcua) Fixed in 2.166.0
  • Fix · GHSA-6wvw-vrw4-363w node-opcua (npm) Fixed in 2.166.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54156
  2. 2026-10-03 Alias added: GHSA-6wvw-vrw4-363w

References

Other 4

  • TI-2026-84561 Authorization bypass in node-opcua lets anonymous clients write CVSS 3.1CRITICAL 9.1
  • TI-2026-48544 node-opcua: Prototype Pollution via internal `fieldsToJson()` implementation (Related to CVE-2024-57086) CVSS 3.1LOW 3.7
  • TI-2026-39065 node-opcua: Missing nonce verification in UserNameIdentityToken authentication CVSS 3.1HIGH 7.7
  • TI-2026-48457 node-opcua: TCP Socket Leak (FIN-WAIT-2) via keepalive reconnection cycle - Resource Exhaustion CVSS 3.1HIGH 7.0

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences