undertow-io/undertow · Security

Undertow is Vulnerable to HTTP Request/Response Smuggling

GHSA ID
GHSA-8v4x-mgvp-p658
CVE ID
CVE-2026-28368
Severity
high
Published
Updated
CVSS
8.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
CVSS v3
8.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Description

A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.

CWEs

References