node-opcua up to 2.165.x UserNameIdentityToken authentication handler opcua_server.ts isValidUser improper authentication

Summaryinfo

A vulnerability was found in node-opcua up to 2.165.x and classified as critical. This impacts the function isValidUser of the file packages/node-opcua-server/source/opcua_server.ts of the component UserNameIdentityToken authentication handler. Such manipulation leads to improper authentication. This vulnerability is referenced as CVE-2026-54155. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in node-opcua up to 2.165.x and classified as critical. Affected by this issue is the function isValidUser of the file packages/node-opcua-server/source/opcua_server.ts of the component UserNameIdentityToken authentication handler. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-54155 since 06/11/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 2.166.0 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

• node-opcua

Version

• 2.165

Website

• Product: https://github.com/node-opcua/node-opcua/

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