CVE-2026-6734 is a high-severity security vulnerability in undici (npm), affecting versions >= 7.23.0, < 7.28.0. It is fixed in 7.28.0, 8.2.0.
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 #4385 and affects all versions through 8.1.0. Patches Upgrade to undici v7.28.0 or v8.2.0 Workarounds Use a separate Socks5ProxyAgent instance per origin, or avoid using Socks5ProxyAgent with multiple origins.
CVE-2026-6734 has a CVSS score of 7.5 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (7.28.0, 8.2.0). Upgrading removes the vulnerable code path.
npm
undici (>= 7.23.0, < 7.28.0)undici (>= 8.0.0, < 8.2.0)undici → 7.28.0 (npm)undici → 8.2.0 (npm)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-6734 is reachable in your applications. Explore open-source security for your team.
See if CVE-2026-6734 is reachable in your applications. Get a demo
Upgrade the following packages to resolve this vulnerability:
undici to 7.28.0 or laterundici to 8.2.0 or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-6734 is a high-severity security vulnerability in undici (npm), affecting versions >= 7.23.0, < 7.28.0. It is fixed in 7.28.0, 8.2.0.
CVE-2026-6734 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
undici (npm) versions >= 7.23.0, < 7.28.0 is affected.
Yes. CVE-2026-6734 is fixed in 7.28.0, 8.2.0. Upgrade to this version or later.
Whether CVE-2026-6734 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
undici to 7.28.0 or laterundici to 8.2.0 or later