HTTP Request Smuggling in Ruby WEBrick

Publication date: 2026-07-02

Last updated on: 2026-07-02

Assigner: MITRE

Description

ruby webrick through v1.9.2 WEBrick reparses trailer Content-Length into canonical request state, enabling request smuggling.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-02

Last Modified

2026-07-02

Generated

2026-07-03

AI Q&A

2026-07-03

EPSS Evaluated

N/A

NVD

CVE-2026-38969

Affected Vendors & Products

Vendor	Product	Version / Range
ruby	webrick	1.9.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in ruby webrick versions through v1.9.2. It involves WEBrick reparsing the trailer Content-Length header into the canonical request state, which enables an attacker to perform request smuggling.

Impact Analysis

By exploiting this vulnerability, an attacker can perform HTTP request smuggling. This can lead to various impacts such as bypassing security controls, interfering with the processing of legitimate requests, or causing unexpected behavior in web applications.

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