← Vulnerability feed

Vulnerability record · CVE-2026-42579 · published 13 May 2026

CVE-2026-42579: Netty improper input validation vulnerability

Netty · Netty

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

9.1 CVSS 3.1 Critical EPSS 0.85% · top 43.6% CWE-20 · Improper input validationCWE-400 · Uncontrolled resource consumption
9.1CVSS 3.1 base score
0.85%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
18References, 2 tagged exploit
18 Sep 2026Last modified by NVD

Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's DNS codec does not enforce RFC 1035 domain name constraints during either encoding or decoding. This creates a bidirectional attack surface: malicious DNS responses can exploit the decoder, and user-influenced hostnames can exploit the encoder. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

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

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-cm33-6792-r9fm ExploitMitigationVendor Advisory
https://access.redhat.com/errata/RHSA-2026:23808
https://access.redhat.com/errata/RHSA-2026:24502
https://access.redhat.com/errata/RHSA-2026:25123
https://access.redhat.com/errata/RHSA-2026:28010
https://access.redhat.com/errata/RHSA-2026:36820
https://access.redhat.com/errata/RHSA-2026:37390
https://access.redhat.com/errata/RHSA-2026:49700
https://access.redhat.com/errata/RHSA-2026:49701
https://access.redhat.com/errata/RHSA-2026:53644
https://access.redhat.com/errata/RHSA-2026:53645
https://access.redhat.com/errata/RHSA-2026:53646
https://access.redhat.com/errata/RHSA-2026:54435
https://access.redhat.com/errata/RHSA-2026:65126
https://access.redhat.com/security/cve/CVE-2026-42579
https://bugzilla.redhat.com/show_bug.cgi?id=2477217
https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fm ExploitMitigationVendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42579.json

Track CVE-2026-42579 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

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

7.5CVE-2023-44487HTTP/2 Rapid Reset stream cancellation denial of serviceThe HTTP/2 protocol permits a client to cancel many streams quickly, and the server's handling of those resets consumes disproportionate resources. T…KEVEPSS 100%analysed10.0CVE-2026-47691Netty insufficient verification of data authenticity vulnerabilityNetty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's `…EPSS 0.36%10.0CVE-2026-45674Netty insufficient verification of data authenticity vulnerabilityNetty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's D…EPSS 0.36%9.8CVE-2026-42581Netty http request smuggling vulnerabilityNetty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting…EPSS 0.68%9.1CVE-2026-75595Netty vulnerabilityNetty is an asynchronous, event-driven network application framework. Prior to 4.1.137.Fina and 4.2.17.Final, io.netty.handler.ssl.SslClientHelloHand…EPSS 0.46%9.1CVE-2026-56820Netty improper certificate validation vulnerabilityNetty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and prior to 4…EPSS 0.31%9.1CVE-2026-42584Netty http request smuggling vulnerabilityNetty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound res…EPSS 0.72%9.1CVE-2019-20444Netty http request smuggling vulnerabilityHttpObjectDecoder.java in Netty before 4.1.44 allows an HTTP header that lacks a colon, which might be interpreted as a separate header with an incor…EPSS 8.9%

Source: NIST National Vulnerability Database (record CVE-2026-42579), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.