cookie-sign (npm) · Malicious Code
Affects cookie-signSource GCVE Database
Malicious package : remove cookie-sign and rotate any secrets on hosts that installed it.
Data as of 13 Jul 2026, 09:28 UTC
Malicious package
Published to npm · OSV MAL-2026-10411
What to do
Remove cookie-sign from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmcookie-sign | Affected
| Fixed in– |
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Description
The npm package 'cookie-sign' version 2.3.5 is a malicious package masquerading as a cookie-signing utility. Upon installation, it spawns a detached child process that decodes a hardcoded URL and sends the installer's entire environment variables to this attacker-controlled server. The server responds with code that is immediately executed in the installer's Node.js process, enabling remote code execution and exfiltration of sensitive environment data such as cloud credentials and tokens. The malicious URL is obfuscated and hidden under a decoy environment variable name. This package misrepresents its functionality to evade detection.