Netty DNS Codec Domain Constraint Bypass (<=4.2.13, <=4.1.133)
CVE-2026-42579 Published on May 13, 2026

Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder)
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.

NVD

Vulnerability Analysis

CVE-2026-42579 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Types

Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

What is a Resource Exhaustion Vulnerability?

The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

CVE-2026-42579 has been classified to as a Resource Exhaustion vulnerability or weakness.

What is a Poison Null Byte Vulnerability?

The product does not properly handle null bytes or NUL characters when passing data between different representations or components.

CVE-2026-42579 has been classified to as a Poison Null Byte vulnerability or weakness.

Improper Validation of Syntactic Correctness of Input

The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.


Products Associated with CVE-2026-42579

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-42579 are published in these products:

Netty
 
Canonical Ubuntu Linux
 
Red Hat Cryostat
 
Red Hat Openshift Devspaces
 
Red Hat Quarkus
 
Red Hat Amq Streams
 
Red Hat Serverless
 
Red Hat Camel Quarkus
 
Red Hat Camel Spring Boot
 
Red Hat Service Registry
 
Red Hat Apicurio Registry
 
Red Hat Debezium
 
Red Hat Build Keycloak
 
Red Hat Optaplanner
 
Red Hat Jboss Data Grid
 
Red Hat Enterprise Linux Ai
 
Red Hat Jboss Fuse
 
Red Hat Jboss Enterprise Application Platform
 
Red Hat Jbosseapxp
 
Red Hat Openshift Ai
 
Red Hat Jboss Enterprise Bpms Platform
 
Red Hat Single Sign On
 
Red Hat Apache Camel Spring Boot
 

Affected Versions

netty: Red Hat Cryostat 4 on RHEL 9: Red Hat Cryostat 4 on RHEL 9: Red Hat Cryostat 4 on RHEL 9: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16: Red Hat build of Quarkus 3.27.4: Red Hat build of Quarkus 3.33.2: Red Hat OpenShift Dev Spaces 3.28: Red Hat OpenShift Dev Spaces 3.28: Red Hat OpenShift Dev Spaces 3.28: Red Hat OpenShift Dev Spaces 3.29: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat OpenShift Serverless: Red Hat build of Apache Camel 4 for Quarkus 3: Red Hat build of Apicurio Registry 2: Red Hat build of Apicurio Registry 3: Red Hat build of Debezium 3: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat Build of Keycloak: Red Hat build of OptaPlanner 8: Red Hat Data Grid 8: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Fuse 7: Red Hat JBoss Enterprise Application Platform 7: Red Hat JBoss Enterprise Application Platform 8: Red Hat JBoss Enterprise Application Platform Expansion Pack: Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat OpenShift AI (RHOAI): Red Hat Process Automation 7: Red Hat Single Sign-On 7: Red Hat streams for Apache Kafka 2: Red Hat streams for Apache Kafka 3:

Exploit Probability

EPSS
0.42%
Percentile
33.32%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.