Netty <=4.2.15 DNS Cache Poisoning via DnsResolveContext
CVE-2026-47691 Published on June 12, 2026

Netty has Insufficient Bailiwick Validation for NS Records
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's `DnsResolveContext` insufficiently validates the bailiwick of NS records, enabling DNS Cache Poisoning. An attacker controlling an authoritative name server for a subdomain can poison the cache for parent domains (like `.co.uk`). In `io.netty.resolver.dns.DnsResolveContext.AuthoritativeNameServerList#add` method accepts any NS record from the AUTHORITY section as long as the record's name is a suffix of the questionName. Subsequently, the `handleWithAdditional` method caches the associated A records from the ADDITIONAL section directly into the `authoritativeDnsServerCache` under the parent domain's key. This bypasses standard bailiwick rules, where a server authoritative for a subdomain should not be trusted to provide authoritative records for its parent. The poisoned cache is then used for all future resolutions under the parent domain's key. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

NVD

Vulnerability Analysis

CVE-2026-47691 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

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

Weakness Types

Insufficient Verification of Data Authenticity

The software does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.

Origin Validation Error

The software does not properly verify that the source of data or communication is valid.


Products Associated with CVE-2026-47691

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-47691 are published in these products:

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

Affected Versions

netty: Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1: Red Hat build of Quarkus 3.27.4.SP1: Red Hat build of Quarkus 3.33.2.SP1: Red Hat Cryostat 4: Red Hat OpenShift Serverless: Red Hat build of Apache Camel - HawtIO 4: Red Hat build of Apache Camel 4 for Quarkus 3: Red Hat build of Apache Camel for Spring Boot 4: Red Hat build of Apicurio Registry 3: Red Hat build of Debezium 3: Red Hat Build of Keycloak: Red Hat Data Grid 8: 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 Dev Spaces: Red Hat streams for Apache Kafka 2: Red Hat streams for Apache Kafka 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Single Sign-On 7:

Exploit Probability

EPSS
0.24%
Percentile
14.87%

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.