Review reviewHigh

CVE-2026-44249

netty netty, Cryostat 4 on RHEL 9, Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1

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.

CVSS
8.1
EPSS
0.57%
44.1% percentile
CISA KEV
Not listed
Published
2026.06.12
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.57%
Technical severityCVSS 8.1

Vulnerability overview

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.

Affected product and versions

Product
netty netty, Cryostat 4 on RHEL 9, Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1
Affected versions
>= >= 4.2.0.Final, < 4.2.15.Final, >= < 4.1.135.Final, < 4.1.135, >= 4.2.0 < 4.2.15
Fixed versions
4.1.135, 4.2.15

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that netty netty, Cryostat 4 on RHEL 9, Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-1287, CWE-284, CWE-697