CVE-2026-9697

HighCVSS 7.4

Published: 17/06/2026(UTC)Updated: 07/07/2026(UTC)Translated: 08/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.46%

37th percentile — higher than 37% of all known CVEs

Summary

A vulnerability in the undici library causes ProxyAgent to silently drop the requestTls option when configured with a SOCKS5 proxy URI. HTTPS connections through the SOCKS5 tunnel fall back to Node's default trust store, ignoring user-configured TLS settings.

Risk Assessment

Organizations relying on requestTls.ca for certificate pinning to an internal CA lose this protection when using SOCKS5 proxy. An attacker can perform MITM attacks to read and tamper with HTTPS traffic, compromising data confidentiality and integrity.

Recommendation

Upgrade undici to version 7.28.0 or 8.5.0 immediately. If an upgrade is not possible, temporarily use an HTTP proxy instead of SOCKS5, where requestTls is honored correctly.

Original NVD description (English source)

Impact: undici's ProxyAgent silently drops the requestTls option when configured with a SOCKS5 proxy URI (socks5:// or socks://). The target HTTPS connection through the SOCKS5 tunnel falls back to Node's default trust store, ignoring user-configured ca, cert, key, rejectUnauthorized, and servername settings. Applications that pin to an internal or corporate CA via requestTls.ca will, when their proxy URI is SOCKS5, get the default Mozilla CA bundle as the trust anchor instead. Any cert signed by any publicly-trusted CA for the target hostname is accepted, breaking the intended pin and enabling MITM read and tamper of the HTTPS exchange. Affected applications are those that use undici's ProxyAgent (or Socks5ProxyAgent directly) with SOCKS5 AND rely on requestTls for TLS scope restriction. The bug was introduced in undici 7.23.0 when SOCKS5 support was added. Patches: Upgrade to undici v7.28.0 or v8.5.0. Workarounds: No workaround is available within the SOCKS5 path. If a SOCKS5 proxy with TLS scope restriction is required and an upgrade is not yet possible, route the traffic through an HTTP-proxy ProxyAgent instead, where requestTls is honored correctly.