HTTP Request Smuggling Affecting io.undertow:undertow-core package, versions [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-JAVA-IOUNDERTOW-15967938
- published10 Apr 2026
- disclosed27 Mar 2026
- creditUnknown
Introduced: 27 Mar 2026
NewCVE-2026-28367 (opens in a new tab)How to fix?
There is no fixed version for io.undertow:undertow-core.
Overview
io.undertow:undertow-core is a Java web server based on non-blocking IO.
Affected versions of this package are vulnerable to HTTP Request Smuggling via the proxy server. An attacker can gain unauthorized access or manipulate web requests by sending specially crafted header block terminators (\r\r\r) to exploit differences in how certain proxy servers interpret HTTP requests.