---
id: "CVE-2026-119186"
kind: "vulnerability"
aliases: ["CVE-2026-119186"]
title: "node-forge: AES-GCM decryption accepts unauthenticated ciphertext when tagLength is zero"
severity: "medium"
cvss: 5.9
epss: 0.00206
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["javascript", "node-forge", "npm", "package"]
not_affected_if: ["default-tag-length", "fixed-tag-length"]
published_at: "2026-10-29T20:17:29+00:00"
first_seen_at: "2026-10-29T20:26:50+00:00"
updated_at: "2026-10-30T18:23:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-119186", "first_seen_at": "2026-10-29T20:26:50+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-119186", "first_seen_at": "2026-10-30T18:23:39+00:00"}]
---

# node-forge: AES-GCM decryption accepts unauthenticated ciphertext when tagLength is zero

node-forge is a JavaScript TLS and crypto library. Before 1.4.1, an AES-GCM decryption with a tagLength that converts to zero and an empty tag lets an attacker's modified ciphertext pass as authentic.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `npm ls node-forge` to find the installed version.
- Search the code for `forge.cipher.createDecipher` and check whether `tagLength` is taken from received data or may be unset or zero.

## Fix

- node-forge: move to `1.4.1`

## Timeline

- 2026-10-29T20:26:50+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-119186
- 2026-10-30T18:23:39+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-119186

## From the sources

Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, node-forge did not validate the AES-GCM tagLength option passed to start() during decryption through forge.cipher.createDecipher(). When an application derived tagLength from received data or used an unset or zero-like configuration value, a value that converted to zero together with an empty or missing authentication tag caused the calculated and supplied tags to compare as empty, so decipher.finish() accepted unauthenticated ciphertext. Applications that omit tagLength to use the 128-bit default or pass a fixed valid tag length are unaffected. This issue is fixed in version 1.4.1.

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