CVE-2026-28367

HIGH8.7EPSS 0.05%

Undertow is Vulnerable to HTTP Request/Response Smuggling

Published: 3/27/2026Modified: 3/31/2026
Also known as:GHSA-3gv6-g396-9v4r

Description

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.

Affected packages (2)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1HIGH8.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

References (5)