Vulnerability · Published Jun 17, 2026 · Assigned by openjs

CVE-2026-6734undici vulnerable to cross-origin request routing via SOCKS5 proxy pool reuse

High 7.5

In plain English

A high-severity security flaw in undici from undici. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.3%top 71.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8nodejs1:24.18.0-1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9nodejs1:24.18.0-1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8nodejs-devel1:24.18.0-1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9nodejs-devel1:24.18.0-1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8nodejs-docs1:24.18.0-1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9nodejs-docs1:24.18.0-1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8nodejs-full-i18n1:24.18.0-1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9nodejs-full-i18n1:24.18.0-1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8nodejs-libs1:24.18.0-1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9nodejs-libs1:24.18.0-1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8nodejs-nodemon3.0.3-1.module_el8.10.0+4061+f8ceeab9ALSA-2026:39868
AlmaLinux:9nodejs-nodemon3.0.3-3.module_el9.7.0+209+ecf6523eALSA-2026:35891
AlmaLinux:8nodejs-packaging2021.06-6.module_el8.10.0+4086+70facd4aALSA-2026:39868
AlmaLinux:9nodejs-packaging2021.06-6.module_el9.7.0+209+ecf6523eALSA-2026:35891
AlmaLinux:8nodejs-packaging-bundler2021.06-6.module_el8.10.0+4086+70facd4aALSA-2026:39868
AlmaLinux:9nodejs-packaging-bundler2021.06-6.module_el9.7.0+209+ecf6523eALSA-2026:35891
AlmaLinux:10nodejs241:24.18.0-1.el10_2ALSA-2026:35841
AlmaLinux:10nodejs24-devel1:24.18.0-1.el10_2ALSA-2026:35841
AlmaLinux:10nodejs24-docs1:24.18.0-1.el10_2ALSA-2026:35841
AlmaLinux:10nodejs24-full-i18n1:24.18.0-1.el10_2ALSA-2026:35841
AlmaLinux:10nodejs24-libs1:24.18.0-1.el10_2ALSA-2026:35841
AlmaLinux:10nodejs24-npm1:11.16.0-1.24.18.0.1.el10_2ALSA-2026:35841
AlmaLinux:8npm1:11.16.0-1.24.18.0.1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9npm1:11.16.0-1.24.18.0.1.module_el9.8.0+277+61fc613eALSA-2026:35891
AlmaLinux:8v8-13.6-devel3:13.6.233.17-1.24.18.0.1.module_el8.10.0+4228+2938bc94ALSA-2026:39868
AlmaLinux:9v8-13.6-devel3:13.6.233.17-1.24.18.0.1.module_el9.8.0+277+61fc613eALSA-2026:35891
Debian:13node-undicino fix listedDEBIAN-CVE-2026-6734
Debian:14node-undici8.5.0+dfsg+~cs3.2.0-1DEBIAN-CVE-2026-6734
Rocky Linux:8nodejs1:24.18.0-1.module+el8.10.0+40252+a58646bcRLSA-2026:39868
Rocky Linux:8nodejs-nodemon0:3.0.3-1.module+el8.10.0+2084+ab509703RLSA-2026:39868
Rocky Linux:9nodejs-nodemon0:3.0.3-3.module+el9.7.0+40025+0e0cf6b2RLSA-2026:35891
Rocky Linux:8nodejs-packaging0:2021.06-6.module+el8.10.0+40171+8fa9c325RLSA-2026:39868
Rocky Linux:8nodejs-packaging0:2021.06-6.module+el8.10.0+40172+38f6fdd1RLSA-2026:39868
Rocky Linux:8nodejs-packaging0:2021.06-6.module+el8.10.0+40048+6d99f608RLSA-2026:39868
Rocky Linux:9nodejs-packaging0:2021.06-6.module+el9.7.0+40052+e32ea525RLSA-2026:35891
Rocky Linux:9nodejs-packaging0:2021.06-6.module+el9.7.0+40165+d075e3f2RLSA-2026:35891
Rocky Linux:9nodejs-packaging0:2021.06-6.module+el9.7.0+40153+4d595597RLSA-2026:35891
Rocky Linux:10nodejs241:24.18.0-1.el10_2RLSA-2026:35841
Ubuntu:24.04:LTSnode-undicino fix listedUBUNTU-CVE-2026-6734
Ubuntu:25.10node-undicino fix listedUBUNTU-CVE-2026-6734
Ubuntu:26.04:LTSnode-undicino fix listedUBUNTU-CVE-2026-6734
Ubuntu:26.10node-undicino fix listedUBUNTU-CVE-2026-6734
npmundici7.28.0GHSA-hm92-r4w5-c3mj
npmundici8.2.0GHSA-hm92-r4w5-c3mj

Affected products (as reported)

VendorProductVersions
undici undici 7.23.0 – before 7.26.08.0.0 – before 8.2.0

Weakness: CWE-346, CWE-940 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References