HTTP Request Smuggling Affecting undici package, versions <6.24.0>=7.0.0-alpha.1 <7.24.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
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-15518061
- published13 Mar 2026
- disclosed12 Mar 2026
- creditUnknown
Introduced: 12 Mar 2026
NewCVE-2026-1525 (opens in a new tab)How to fix?
Upgrade undici to version 6.24.0, 7.24.0 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 HTTP Request Smuggling in the processHeader() while handling HTTP/1.1 requests containing duplicate Content-Length headers with differing casing. An attacker can bypass access controls, poison caches, hijack credentials, or cause service disruption by sending specially crafted HTTP requests that are interpreted inconsistently by proxies and backend servers.