Vulnerability in Undici

CVE-2026-120222

undici is an HTTP client for Node.js. In versions 7.0.0 through 7.30.1 and 8.0.0 through 8.12.3, when the cache interceptor is composed with a downstream handler that throws during response processing (such as the built-in dump interceptor exceeding its maxSize, or the decompress interceptor rejecting more than five Content-Encoding values), a throw raised asynchronously while a cached response is replayed escapes as an uncaught exception or unhandled promise rejection and terminates the Node.js process. A malicious or compromised HTTP server can crash any such client by serving a cacheable response that triggers the throw on replay, including on a 304 revalidation of a stale entry, so the impact is availability only. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later. As a workaround, avoid composing the cache interceptor with a response handler that throws during response processing until upgrading.

Published 2026-11-06 · last modified 2026-11-06.