CVE-2026-44249

Name: CVE-2026-44249
Creator: NVD / NIST
Published: 2026-06-11T22:16:56.707+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 0.41%

Last modified Jun 17, 2026

CVE-2026-44249 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). EPSS estimates a 0.41% chance of exploitation in the next 30 days.

Description

Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Metrics

CVSS 3.1

8.1/10

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

EPSS Probability

0.41%

32.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Netty	Netty	< 4.1.135
Netty	Netty	>= 4.2.0, < 4.2.15

References

https://github.com/netty/netty/releases/tag/netty-4.1.135.FinalRelease Notes
https://github.com/netty/netty/releases/tag/netty-4.2.15.FinalRelease Notes
https://github.com/netty/netty/security/advisories/GHSA-3qp7-7mw8-wx86Vendor Advisory

Timeline

Published: Jun 11, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-44249?

How severe is CVE-2026-44249?

CVE-2026-44249 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.

How do I fix CVE-2026-44249?

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-2026-44249?

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

Scan your code now

Source: NVD / NIST