Origin Validation Error Affecting undici package, versions >=7.23.0 <7.28.0>=8.0.0 <8.2.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-UNDICI-17372667
- published18 Jun 2026
- disclosed17 Jun 2026
- creditNikita Skovoroda
Introduced: 17 Jun 2026
NewCVE-2026-6734 (opens in a new tab)How to fix?
Upgrade undici to version 7.28.0, 8.2.0 or higher.
Overview
undici is an An HTTP/1.1 client, written from scratch for Node.js
Affected versions of this package are vulnerable to Origin Validation Error in the Socks5ProxyAgent. An attacker can intercept or redirect sensitive data, including credentials and request payloads, to unintended origins by exploiting improper verification of origin matching when reusing connection pools. This may also result in responses from incorrect origins being trusted and can lead to silent downgrading of HTTPS requests to HTTP.
Note: This is only exploitable if the application uses Socks5ProxyAgent (directly or via setGlobalDispatcher) and makes requests to more than one origin.
Workaround
This vulnerability can be mitigated by using a separate Socks5ProxyAgent instance per origin or by avoiding the use of Socks5ProxyAgent with multiple origins.