CVE-2026-28369 — Undertow: undertow: request smuggling via malformed http request headers
A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by strippin…
Published: 2026-03-27 · CVSS: 8.7 · CVSS 3.1
A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7