Bug 2488439 (CVE-2026-47691) - CVE-2026-47691 io.netty/netty-resolver-dns: Netty has Insufficient Bailiwick Validation for NS Records
Summary: CVE-2026-47691 io.netty/netty-resolver-dns: Netty has Insufficient Bailiwick ...
Keywords:
Status: NEW
Alias: CVE-2026-47691
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-12 16:03 UTC by OSIDB Bzimport
Modified: 2026-08-04 13:59 UTC (History)
91 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

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System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:26586 0 None None None 2026-06-17 23:05:43 UTC
Red Hat Product Errata RHSA-2026:34608 0 None None None 2026-07-02 00:04:29 UTC
Red Hat Product Errata RHSA-2026:37390 0 None None None 2026-07-09 15:29:40 UTC
Red Hat Product Errata RHSA-2026:41951 0 None None None 2026-07-20 11:57:41 UTC
Red Hat Product Errata RHSA-2026:48151 0 None None None 2026-07-29 19:55:23 UTC
Red Hat Product Errata RHSA-2026:49700 0 None None None 2026-08-03 15:41:48 UTC
Red Hat Product Errata RHSA-2026:49701 0 None None None 2026-08-03 15:41:00 UTC
Red Hat Product Errata RHSA-2026:50085 0 None None None 2026-08-04 13:59:49 UTC

Description OSIDB Bzimport 2026-06-12 16:03:08 UTC 
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.
Comment 1 errata-xmlrpc 2026-06-17 23:05:43 UTC 
This issue has been addressed in the following products:

  Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1

Via RHSA-2026:26586 https://access.redhat.com/errata/RHSA-2026:26586
Comment 2 errata-xmlrpc 2026-07-02 00:04:24 UTC 
This issue has been addressed in the following products:

  Streams for Apache Kafka 2.9.4

Via RHSA-2026:34608 https://access.redhat.com/errata/RHSA-2026:34608
Comment 4 errata-xmlrpc 2026-07-09 15:29:35 UTC 
This issue has been addressed in the following products:

  Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16

Via RHSA-2026:37390 https://access.redhat.com/errata/RHSA-2026:37390
Comment 5 errata-xmlrpc 2026-07-20 11:57:36 UTC 
This issue has been addressed in the following products:

  Red Hat Data Grid 8.6.2

Via RHSA-2026:41951 https://access.redhat.com/errata/RHSA-2026:41951
Comment 6 errata-xmlrpc 2026-07-29 19:55:18 UTC 
This issue has been addressed in the following products:

  Cryostat 4 on RHEL 9

Via RHSA-2026:48151 https://access.redhat.com/errata/RHSA-2026:48151
Comment 7 errata-xmlrpc 2026-08-03 15:40:55 UTC 
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1

Via RHSA-2026:49701 https://access.redhat.com/errata/RHSA-2026:49701
Comment 8 errata-xmlrpc 2026-08-03 15:41:43 UTC 
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
  Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10

Via RHSA-2026:49700 https://access.redhat.com/errata/RHSA-2026:49700
Comment 9 errata-xmlrpc 2026-08-04 13:59:44 UTC 
This issue has been addressed in the following products:

  Red Hat JBoss Enterprise Application Platform 8.1

Via RHSA-2026:50085 https://access.redhat.com/errata/RHSA-2026:50085
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