CVE-2026-6734

Aliases:GHSA-hm92-r4w5-c3mj
Advisory lineage Upstream: 0 Downstream: 9
PUBLISHED
Published: 17 Jun 2026, 16:36
Last modified:21 Jul 2026, 12:05

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.32% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

17 Jun 2026, 16:36
Published
Vulnerability first disclosed
21 Jul 2026, 12:05
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.32%• Percentile: 23%

Techniques & Countermeasures

  • CWE-346•Origin Validation Error

    The product does not properly verify that the source of data or communication is valid.

  • CWE-940•Improper Verification of Source of a Communication Channel

    The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.

Affected Systems

  • Npm•undici

    ≥ 7.23.0, < 7.28.0 | ≥ 8.0.0, < 8.2.0

  • undici•undici

    ≥ 7.23.0, < 7.26.0 | ≥ 8.0.0, < 8.2.0

References (19)