---
id: "MAL-2026-17374"
kind: "package"
aliases: ["MAL-2026-17374"]
title: "Malicious code in @rennnpm/baileys (npm)"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "@rennnpm/baileys", "fixed": [], "affected": "all versions", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["malicious", "package"]
not_affected_if: []
published_at: "2026-10-29T13:25:19+00:00"
first_seen_at: "2026-10-29T14:24:36+00:00"
updated_at: "2026-10-29T14:30:57+00:00"
sources: [{"source": "osv-malicious", "url": "https://osv.dev/vulnerability/MAL-2026-17374", "first_seen_at": "2026-10-29T14:24:36+00:00"}]
---

# Malicious code in @rennnpm/baileys (npm)

## Affected

- npm:@rennnpm/baileys affected all versions fixed ?

## Timeline

- 2026-10-29T14:24:36+00:00 osv-malicious https://osv.dev/vulnerability/MAL-2026-17374

## From the sources

This package is part of a large family (100+ identified as of September 2026) of near-identical
forks of the Baileys WhatsApp Web library that inject a covert channel-subscription action into
the WhatsApp socket layer. On connect, the injected code issues an authenticated `w:mex` FOLLOW
query (query_id 7871414976211147) against one or more attacker-chosen WhatsApp Channel/Newsletter
JIDs, using the installer's own authenticated WhatsApp session -- silently subscribing the
victim's account to channels it never asked to join.

The target JID(s) are hidden from casual source review via one of several obfuscation techniques
observed across the family: a plain string literal, base64 encoding, base64+XOR, or a char-code
array reconstructed at runtime. Some variants instead fetch a mutable, attacker-controlled remote
JSON/JS list of target JIDs from GitHub or another host at runtime, letting the target list change
after installation without a new npm publish. Every sample in the family shares the same underlying
mechanism (a wrapped/patched socket-connect routine that fires the FOLLOW query some seconds after
connect), even though the package name, JID value(s), and obfuscation/delivery method differ per
fork.

The malicious action abuses the installer's own authenticated WhatsApp session to gain reach and
subscribers for attacker-controlled channels; it does not exfiltrate credentials, establish
persistence, or execute arbitrary remote code.

Affected package: @rennnpm/baileys (npm), version(s): 1.0.0.

---
_-= Per source details. Do not edit below this line.=-_

## Source: amazon-inspector (1147bf0a20408ab406838da0e6aa5a2086deb1afe6651013a6081714ada641ff)
package.json declares the `libsignal` dependency as `github:tenka-san/libsignal-node`, a bare GitHub reference to a personal user's fork with no commit SHA, tag, or version constraint. On `npm install`, npm clones the default branch's current HEAD and runs any lifecycle scripts the fetched repository declares, executing that code on the installer's machine with no integrity check. Whoever controls the `tenka-san/libsignal-node` repository can change the code at any time, and every installer of this package will run whatever is at HEAD at that moment. The upstream `@whiskeysockets/baileys` package resolves `libsignal` from the npm registry at a pinned version; substituting a mutable third-party git reference in this fork replaces a registry-integrity-checked dependency with an unpinned attacker-controllable code source.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_