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High

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

  • Disclosed: 19.06.2026
  • Updated: 11.10.2026 10:22

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.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package undici >= 7.23.0, < 7.28.0, >= 8.0.0, < 8.2.0 7.28.0, 8.2.0

References

CVSS score 7.5/10
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-346
Platform
npm
Package
undici
Disclosed
19.06.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-hm92-r4w5-c3mj - CC BY 4.0

Vulnerability history: undici

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (46) in the archive
Total entries
46
First → latest
06.2022 09.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 13
  • Medium 21
  • Low 12

Disclosures per year

Severity:
  1. undici vulnerable to Denial of Service via unrequested WebSocket subprotocol
    High · 7.5 CVE-2026-19534 >= 6.7.0, < 6.28.1, >= 7.0.0, < 7.29.1, >= 8.0.0, < 8.10.2 6.28.1, 7.29.1, 8.10.2
  2. undici vulnerable to TLS certificate validation bypass via dropped connect options in BalancedPool
    High · 7.4 CVE-2026-84961 >= 7.24.1, < 7.29.1, >= 8.0.0, < 8.10.2 7.29.1, 8.10.2
  3. undici vulnerable to cross-origin cache poisoning via missing origin isolation in interceptors
    High · 7.4 CVE-2026-85152 >= 8.10.0, < 8.10.2 8.10.2
  4. undici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directives
    High · 7.4 CVE-2026-13697 >= 7.0.0, < 7.29.0, >= 8.0.0, < 8.9.0 7.29.0, 8.9.0
  5. undici WebSocket client vulnerable to denial of service via fragment count bypass
    High · 7.5 CVE-2026-12151 < 6.27.0, >= 7.0.0, < 7.28.0, >= 8.0.0, < 8.5.0 6.27.0, 7.28.0, 8.5.0
  6. undici vulnerable to cross-origin request routing via SOCKS5 proxy pool reuse this entry
    High · 7.5 CVE-2026-6734 >= 7.23.0, < 7.28.0, >= 8.0.0, < 8.2.0 7.28.0, 8.2.0
  7. undici vulnerable to TLS certificate validation bypass via dropped requestTls in SOCKS5 ProxyAgent
    High · 7.4 CVE-2026-9697 >= 7.23.0, < 7.28.0, >= 8.0.0, < 8.5.0 7.28.0, 8.5.0
  8. undici WebSocket client vulnerable to denial of service via cumulative fragment bypass
    High · 7.5 CVE-2026-9675 >= 8.0.0, < 8.5.0 8.5.0
  9. Undici has Unbounded Memory Consumption in WebSocket permessage-deflate Decompression
    High · 7.5 CVE-2026-1526 < 6.24.0, >= 7.0.0, < 7.24.0 6.24.0, 7.24.0
  10. Undici has Unhandled Exception in WebSocket Client Due to Invalid server_max_window_bits Validation
    High · 7.5 CVE-2026-2229 < 6.24.0, >= 7.0.0, < 7.24.0 6.24.0, 7.24.0
  11. Undici: Malicious WebSocket 64-bit length overflows parser and crashes the client
    High · 7.5 CVE-2026-1528 >= 6.0.0, < 6.24.0, >= 7.0.0, < 7.24.0 6.24.0, 7.24.0
  12. Regular Expression Denial of Service in Headers
    High · 7.5 CVE-2023-24807 < 5.19.1 5.19.1
  13. ProxyAgent vulnerable to MITM
    High · 7.7 CVE-2022-32210 >= 4.8.2, < 5.5.1 5.5.1

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