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Vulnerability record · CVE-2026-33870 · published 27 March 2026

CVE-2026-33870: Netty http request smuggling vulnerability

Netty · Netty

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.

7.5 CVSS 3.1 High EPSS 0.70% · top 48.8% CWE-444 · HTTP request smuggling
7.5CVSS 3.1 base score
0.70%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
24References, 1 tagged exploit
14 Sep 2026Last modified by NVD

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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/netty/netty/security/advisories/GHSA-pwqr-wmgm-9rr8 ExploitMitigationVendor Advisory
https://w4ke.info/2025/06/18/funky-chunks.html Technical Description
https://w4ke.info/2025/10/29/funky-chunks-2.html Technical Description
https://www.rfc-editor.org/rfc/rfc9110 Technical Description
https://access.redhat.com/errata/RHSA-2026:10175
https://access.redhat.com/errata/RHSA-2026:10184
https://access.redhat.com/errata/RHSA-2026:13571
https://access.redhat.com/errata/RHSA-2026:14272
https://access.redhat.com/errata/RHSA-2026:14276
https://access.redhat.com/errata/RHSA-2026:17668
https://access.redhat.com/errata/RHSA-2026:17789
https://access.redhat.com/errata/RHSA-2026:18054
https://access.redhat.com/errata/RHSA-2026:18055
https://access.redhat.com/errata/RHSA-2026:18059
https://access.redhat.com/errata/RHSA-2026:22619
https://access.redhat.com/errata/RHSA-2026:34608
https://access.redhat.com/errata/RHSA-2026:65126
https://access.redhat.com/errata/RHSA-2026:7109
https://access.redhat.com/errata/RHSA-2026:7380
https://access.redhat.com/errata/RHSA-2026:8159
https://access.redhat.com/errata/RHSA-2026:8509
https://access.redhat.com/security/cve/CVE-2026-33870
https://bugzilla.redhat.com/show_bug.cgi?id=2452453
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33870.json

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-33870), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.