CVE-2026-6734
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk24th percentile — higher than 24% of all known CVEs
Summary
In the undici library, a vulnerability exists where Socks5ProxyAgent reuses a single connection pool across different origins without verifying that the pool matches the requested origin. This causes cross-origin request routing, potentially leading to credential leakage and silent downgrade of HTTPS to HTTP.
Risk Assessment
The organization risks sending credentials and sensitive data to an unauthorized server and potential man-in-the-middle attacks due to silent HTTPS downgrade to HTTP.
Recommendation
Upgrade undici to version 7.26.0 or 8.2.0 immediately. If an upgrade is not possible, use a separate Socks5ProxyAgent instance per origin or avoid using Socks5ProxyAgent with multiple origins.
Original NVD description (English source)
Impact: When using Socks5ProxyAgent, undici reuses a single connection pool across different origins without verifying that the pool's origin matches the requested origin. All requests are dispatched through the pool connected to the first origin, regardless of the intended destination. This causes cross-origin request routing: credentials and request data intended for origin B are sent to origin A, responses from the wrong origin are trusted, and HTTPS requests may be silently downgraded to HTTP. Impacted users are applications that use Socks5ProxyAgent (directly or via setGlobalDispatcher) and make requests to more than one origin. This was introduced in undici 7.23.0 via PR #4385 and affects all versions through 8.1.0. Patches: Upgrade to undici v7.26.0 or v8.2.0. Workarounds: Use a separate Socks5ProxyAgent instance per origin, or avoid using Socks5ProxyAgent with multiple origins.