A GitHub advisory published Oct 30 covers an authentication bypass in the AES-GCM mode of node-forge, the widely used pure-JavaScript crypto library on npm.

• Bug: start() stored the tagLength option without validation. A value that converts to 0 (0, null, false, '', '0') made the tag truncation compute 16 % 0 = NaN and empty the tag, so decipher.finish() returned true for any ciphertext and additional data.
• Affected: node-forge 1.4.0 and earlier. Fixed: 1.4.1, where start() throws unless the tag length is one NIST SP 800-38D allows (128, 120, 112, 104, 96, 64 or 32 bits). Missing or null uses the 128-bit default.
• Severity: medium, CVSS 5.9, because exploitation needs the application to pass an attacker-influenced or falsy tagLength.

What to do: upgrade to 1.4.1 (check transitive dependencies with npm ls node-forge), and set tagLength explicitly rather than passing it through from config or user input.