CVE-2026-33870 — HTTP Request Smuggling in Netty

CWE-444 — HTTP Request Smuggling8 documents7 sources
Severity
7.5HIGHNVD
EPSS
0.0%
top 97.48%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
NettyDebian Netty
Timeline
PublishedMar 27

Description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NExploitability: 3.9 | Impact: 3.6

Affected Packages3 packages

▶CVEListV5netty/netty< 4.1.132.Final+1
▶NVDnetty/netty4.2.0 — 4.2.10+1
▶debiandebian/netty

🔴Vulnerability Details

3
OSV
CVE-2026-33870: Netty is an asynchronous, event-driven network application framework↗2026-03-27
▶
GHSA
Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing↗2026-03-26
▶
OSV
Netty: HTTP Request Smuggling via Chunked Extension Quoted-String Parsing↗2026-03-26
▶

📋Vendor Advisories

2
Red Hat
io.netty/netty-codec-http: Netty: Request smuggling via incorrect parsing of HTTP/1.1 chunked transfer encoding extension values↗2026-03-27
▶
Debian
CVE-2026-33870: netty - Netty is an asynchronous, event-driven network application framework. In version...↗2026
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-33870 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶

💬Community

1
Bugzilla
CVE-2026-33870 io.netty/netty-codec-http: Netty: Request smuggling via incorrect parsing of HTTP/1.1 chunked transfer encoding extension values↗2026-03-27
▶