CVE-2026-42579

Name: CVE-2026-42579
Creator: NVD / NIST
Published: 2026-05-13T19:17:23.353+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 0.52%

Last modified Jun 17, 2026

CVE-2026-42579 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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. EPSS estimates a 0.52% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

0.52%

40.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Netty	Netty	< 4.1.133
Netty	Netty	>= 4.2.0, < 4.2.13

References

https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fmExploit, Mitigation, Vendor Advisory
https://github.com/netty/netty/security/advisories/GHSA-cm33-6792-r9fmExploit, Mitigation, Vendor Advisory

Timeline

Published: May 13, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-42579?

How severe is CVE-2026-42579?

CVE-2026-42579 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.52% probability of exploitation in the next 30 days.

How do I fix CVE-2026-42579?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-42579?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST