CVE-2026-55553: Node-Modules Urllib

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

urllib is an HTTP client for Node.js that supports authentication, redirects, timeouts, and other request features. Prior to 4.9.1 and 2.44.1, urllib follows redirects through followRedirect but reuses caller-supplied options across origins. In src/HttpClient.ts, #requestInternal recursively calls this.#requestInternal(nextUrl.href, options, requestContext), causing options.headers and auth or digestAuth values to be reused when the redirect target has a different scheme, host, or port. Authorization, Cookie, Proxy-Authorization, x-api-key, x-auth-token, and x-access-token can therefore be sent to an attacker-controlled redirected origin, exposing credentials intended for the original origin and potentially allowing reuse against the original partner API or related services. No user interaction is required. This issue is fixed in versions 2.44.1 and 4.9.1.

Affected products

• Node-Modules Urllib: from 3.0.0, before 4.9.1 (fixed in 4.9.1); before 2.44.1 (fixed in 2.44.1)

Published 2026-08-25. Last modified 2026-09-09.