Use of Insufficiently Random Values Affecting node-undici package, versions *

Note: Versions mentioned in the description apply only to the upstream node-undici package and not the node-undici package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

Undici is an HTTP/1.1 client. Starting in version 4.5.0 and prior to versions 5.28.5, 6.21.1, and 7.2.3, undici uses Math.random() to choose the boundary for a multipart/form-data request. It is known that the output of Math.random() can be predicted if several of its generated values are known. If there is a mechanism in an app that sends multipart requests to an attacker-controlled website, they can use this to leak the necessary values. Therefore, an attacker can tamper with the requests going to the backend APIs if certain conditions are met. This is fixed in versions 5.28.5, 6.21.1, and 7.2.3. As a workaround, do not issue multipart requests to attacker controlled servers.

• https://security-tracker.debian.org/tracker/CVE-2025-22150
• https://blog.securityevaluators.com/hacking-the-javascript-lottery-80cc437e3b7f
• https://github.com/nodejs/undici/blob/8b06b8250907d92fead664b3368f1d2aa27c1f35/lib/web/fetch/body.js#L113
• https://github.com/nodejs/undici/commit/711e20772764c29f6622ddc937c63b6eefdf07d0
• https://github.com/nodejs/undici/commit/c2d78cd19fe4f4c621424491e26ce299e65e934a
• https://github.com/nodejs/undici/commit/c3acc6050b781b827d80c86cbbab34f14458d385
• https://github.com/nodejs/undici/security/advisories/GHSA-c76h-2ccp-4975
• https://hackerone.com/reports/2913312