Is CVE-2026-6734 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-6734 being exploited in the wild.

How severe is CVE-2026-6734?

High severity, with a CVSS score of 7.5, published 17 June 2026.

Which products and versions are affected?

undici (npm) SEMVER:introduced=7.23.0,fixed=7.28.0.

Is there a fix for CVE-2026-6734?

Yes. undici (npm): upgrade to 7.28.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-6734 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-6734?

Check whether you run undici (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-6734: Node.js undici cross-origin request routing in SOCKS5 ProxyAgent

CVE-2026-6734 · Severity: high · CVSS 7.5 · Published 2026-06-17

Undici, a popular HTTP client for Node.js, contains a flaw in how it handles secure proxy connections. When configured to use a SOCKS5 proxy, the library may mistakenly send sensitive data, such as login credentials or private request details, to the wrong website. This could lead to data theft, the acceptance of fraudulent data from incorrect sources, or the accidental bypass of encryption.

Technologies: undici (npm). Vendors: npm.

Quick answers

Is CVE-2026-6734 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-6734 being exploited in the wild.
How severe is CVE-2026-6734?: High severity, with a CVSS score of 7.5, published 17 June 2026.
Which products and versions are affected?: undici (npm) SEMVER:introduced=7.23.0,fixed=7.28.0.
Is there a fix for CVE-2026-6734?: Yes. undici (npm): upgrade to 7.28.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-6734 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-6734?: Check whether you run undici (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

undici (npm): upgrade to 7.28.0 or later
```
npm install undici@7.28.0
```

Technical details

A vulnerability exists in undici's Socks5ProxyAgent where the library reuses a single connection pool across different origins without verifying that the pool's origin matches the requested destination. Consequently, all requests are dispatched through the connection pool established for the first origin visited. An attacker can exploit this to intercept credentials and request data intended for one origin by receiving them at another, or cause the client to trust responses from an incorrect source. Additionally, this flaw can lead to silent HTTPS-to-HTTP downgrades. The issue was introduced in version 7.23.0 and is fixed in versions 7.28.0 and 8.2.0.

Affected products

Node.js undici >= 7.23.0, < 7.28.0; >= 8.0.0, < 8.2.0

Identifiers

CVE-2026-6734
GHSA-hm92-r4w5-c3mj

Timeline

2026-06-17: disclosed
2026-06-17: advisory
2026-06-17: patched

References

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