CVE-2026-54156

7.5 HIGH 0.8% exploit odds Fix listed Denial of service Server

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of service disruption.
Exploit odds: 0.8% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-09-14 17:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-30 19:38 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.8% in the next 30 days (EPSS).
Severity: 7.5 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-09-14 17:17 UTC
Last modified: 2026-09-30 19:38 UTC
Exploit probability: 0.8% · EPSS, next 30 days
Weakness: CWE-770 · Allocation without limits
Record status: Awaiting Analysis

Attack profile CVSS 3.1 · 7.5

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-54156.md and follow it. Check whether this project is affected by CVE-2026-54156. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record