Malicious code in express-chai (npm)
express-chai presents itself as an Express logger middleware impersonating pino, but its exported middleware factory invokes lib/caller.js which decodes a base64-obfuscated URL (https://gray-dyane-31.tiiny.site/index.json) stored in lib/const.js, fetches a JSON payload via axios with a base64-encoded dev-secret-key header, and passes the response's cookie field to new Function.constructor("require", s), then invokes the resulting function with the local require. This grants the operator of the anonymous tiiny.site host arbitrary code execution inside the installer's Node.js process at middleware setup time, with full access to require and the surrounding application context. The destination URL and secret header are base64-encoded rather than plain configuration, and the package's naming, keywords (fast, logger, stream, json), and pino-mirroring script names disguise a remote code loader as a well-known logging library.
MAL-2026-13446 is recorded against 1 package.
Published on 6 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
Details
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| express-chai | — | — |
References
Free Vulnerability Check
BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against MAL-2026-13446 and other known CVE records.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.
Stay up to date with the latest from Boteraser.
We use cookies to improve your experience on our site. By using our site, you consent to cookies.
Manage your cookie preferences below:
Essential cookies enable basic functions and are necessary for the proper function of the website.
CloudFlare provides web performance and security solutions, enhancing site speed and protecting against threats.
Service URL: developers.cloudflare.com (opens in a new window)
These cookies are needed for adding comments on this website.
These cookies are used for managing login functionality on this website.
Statistics cookies collect information anonymously. This information helps us understand how visitors use our website.
Google Analytics is a powerful tool that tracks and analyzes website traffic for informed marketing decisions.
Service URL: policies.google.com (opens in a new window)
You can find more information in our Cookie Policy and Privacy Policy.