Undertow is Vulnerable to HTTP Request/Response Smuggling

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...

EUVD-2026-16698

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...

CVE-2026-28369

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...

CVE-2026-28369

Undertow contains a vulnerability where the first HTTP header line with leading spaces is stripped, violating HTTP standards and enabling request smuggling. Affected component: Undertow HTTP header parsing. Root cause: improper handling that trims leading spaces on the initial header line. Impact...