CVE-2026-1528: Node.js Undici

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

ImpactA server can reply with a WebSocket frame using the 64-bit length form and an extremely large length. undici's ByteParser overflows internal math, ends up in an invalid state, and throws a fatal TypeError that terminates the process. Patches Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.

Affected products

• Node.js Undici: before 6.24.0 (fixed in 6.24.0); from 7.0.0, before 7.24.0 (fixed in 7.24.0)

Published 2026-03-12. Last modified 2026-09-04.