CyberSecBulletin
CVE-2026-44249NVD status: Modified

netty: Improper Access Control

Published Updated By the CyberSecBulletin desk

CVE-2026-44249 is a high-severity improper access control vulnerability in netty, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected netty versions: >= 4.2.0.Final, < 4.2.15.Final; < 4.1.135.Final. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.99% chance of exploitation within 30 days, higher than 63% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of netty you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Nettynetty>= 4.2.0.Final, < 4.2.15.Final; < 4.1.135.FinalNot stated
Red HatCryostat 4 on RHEL 9Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.13.6Not specified in the recordNot stated
Red HatRed Hat AMQ Broker 7.14.1Not specified in the recordNot stated
Red HatRed Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1Not specified in the recordNot stated
Red HatRed Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16Not specified in the recordNot stated
Red HatRed Hat build of Quarkus 3.27.4.SP1Not specified in the recordNot stated
Red HatRed Hat build of Quarkus 3.33.2.SP1Not specified in the recordNot stated
Red HatRed Hat Data Grid 8.6.2Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1.7.GANot specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 10Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 8Not specified in the recordNot stated
Red HatRed Hat JBoss Enterprise Application Platform 8.1 for RHEL 9Not specified in the recordNot stated
Red HatStreams for Apache Kafka 2.9.4Not specified in the recordNot stated
Red HatStreams for Apache Kafka 3.2.1Not specified in the recordNot stated
Red HatRed Hat Offline Knowledge Portal 1.2.12Not specified in the recordNot stated
Red HatRed Hat OpenShift AI 2.25Not specified in the recordNot stated
Red HatRed Hat OpenShift Dev Spaces 3.29Not specified in the recordNot stated
Red HatOpenShift ServerlessNot specified in the recordNot stated
Red HatRed Hat AMQ ClientsNot specified in the recordNot stated
Red HatRed Hat build of Apache Camel 4 for Quarkus 3Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE; 11 further products are omitted here. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (github.com).

Scoring systemScoreSeverityScored by
CVSS 3.18.1HighCNA (github.com)
CVSS 3.18.1HighCNA

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How developers prevent this class of flaw

  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

More Improper Access Control vulnerabilities (CWE-284)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in netty

All netty vulnerabilities

Recent Improper Access Control vulnerabilities

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