CVE-2026-54155 node-opcua: Missing nonce verification in UserNameIdentityToken authentication
An unauthenticated attacker can bypass authentication in node-opcua by forging tokens with empty passwords or replaying captured tokens, leading to account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-54155?
CVE-2026-54155 is a high-severity authentication bypass vulnerability in node-opcua, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
node-opcua is an OPC UA implementation for TypeScript and Node.js. Prior to 2.166.0, the UserNameIdentityToken authentication handler in packages/node-opcua-server/source/opcua_server.ts decrypts an RSA-OAEP password blob but does not verify that the trailing bytes match the current session serverNonce. An unauthenticated remote attacker can obtain the server public key through GetEndpoints and forge a blob whose little-endian length produces an empty password passed to isValidUser, compromising accounts that accept an empty password. Missing nonce binding also allows a captured UserNameIdentityToken ciphertext to be replayed in another session, and SecurityMode=None removes the separate client-signature safeguard. This issue is fixed in version 2.166.0.
Weakness: CWE-347
Which versions are affected by CVE-2026-54155?
2 open source packages ship an affected version, including node-opcua.
| Package | Affected | Fixed in |
|---|---|---|
node-opcua npm | All versions to 2.165.0 | None |
node-opcua npm | All versions to 2.165.0 | None |
How do I fix CVE-2026-54155?
No fix has been published for CVE-2026-54155 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-54155 being exploited?
There is no known exploitation of CVE-2026-54155 in the wild and no public exploit code.
Sources
Also known as GHSA-mq36-523m-x7vv.