High severity · published Jun 17, 2026
CVE-2026-6734
undici vulnerable to cross-origin request routing via SOCKS5 proxy pool reuse
8.8
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 28% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UN
undici · undici
7.23.0 before 7.26.0; 8.0.0 before 8.2.0 · source: vendor, NVD
CO
Cluster Observability Operator 1.5.0 · Red Hat
All versions, or not specified · source: CISA
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
OP
OpenShift Pipelines · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Build of Podman Desktop · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Developer Hub 1.10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Developer Hub 1.9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Hardened Images · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat OpenShift AI (RHOAI) · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6734
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6734
Vendor Advisory
https://cna.openjsf.org/security-advisories.html
Mitigation
https://github.com/nodejs/undici/security/advisories/GHSA-hm92-r4w5-c3mj
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22380
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:22934
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:34342
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:35841
More from undici
9.1
CVE-2026-109383
undici vulnerable to TLS certificate validation bypass via dropped tls options in Agent
9.1
CVE-2026-109829
undici vulnerable to cache poisoning and cross-user disclosure via cross-origin redirects
9.1
CVE-2026-84961
undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool
9.1
CVE-2026-13697
undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives
8.2
CVE-2026-84933
undici vulnerable to cross-user cookie disclosure via Set-Cookie caching in shared caches
