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 redirect interceptor and a shared response cache are used together, an authenticated request that is redirected to a same-origin target has the final response stored under the original request's cache key. That key omits the credential and carries no Vary header, so a later anonymous or different user can be served the first user's private response body. This results in cross-user disclosure of cached private responses. The issue is fixed in undici 7.30.2 and 8.12.4, and users should upgrade to one of those versions or later.