# OpenAI Finds Remote-Code Flaw in Brotli Used by Node.js, Bun and Envoy

By Simon Yoon

Canonical URL: https://www.tokenpost.com/news/technology/39999
Published: 2026-10-24T13:28:05.000Z
Updated: 2026-10-24T13:28:05.000Z
Section: Technology

> The flaw can let attackers compromise unpatched servers or clients that process compressed data.

OpenAI’s red-team testing found an unauthenticated remote-code-execution flaw in Brotli, a widely used compression library built into Node.js, Bun and Envoy, putting unpatched systems at risk of takeover.

OpenAI said attackers can exploit the flaw by sending malicious compressed data to an unpatched server. A malicious server could also take control of a client that accepts compressed data. The issue requires no authentication, so an attacker does not need an account on the target system to exploit it.

The underlying code issue was fixed in Brotli’s source in February, but OpenAI said it was not identified as a security vulnerability at the time. Software that bundles Brotli must also be updated, so the source-code fix alone does not protect systems running affected products.

Node.js, Bun and Envoy are among the software packages that include Brotli. Crypto infrastructure that uses unpatched versions of those products may therefore face exposure to attacks through compressed data.