Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records
Summary
Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses.
Details
In io.netty.resolver.dns.DnsResolveContext#buildAliasMap, the resolver processes the ANSWER section of a DNS response and blindly caches all CNAME records it finds.
According to https://datatracker.ietf.org/doc/html/rfc5452#section-6
Care must be taken to only accept
data if it is known that the originator is authoritative for the
QNAME or a parent of the QNAME.
One very simple way to achieve this is to only accept data if it is
part of the domain for which the query was intended.Impact
DNS Cache Poisoning (Bailiwick Bypass). Any application using Netty's DNS resolver is impacted.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Java / Kotlin (Maven) | io.netty:netty-resolver-dns | >= 4.2.0.Final, < 4.2.15.Final, < 4.1.135.Final | 4.2.15.Final, 4.1.135.Final |
References
- https://github.com/netty/netty/security/advisories/GHSA-676x-f7gg-47vc
- https://nvd.nist.gov/vuln/detail/CVE-2026-45674
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45674.json
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final
- https://github.com/netty/netty
- https://bugzilla.redhat.com/show_bug.cgi?id=2488400
- https://access.redhat.com/security/cve/CVE-2026-45674
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:62260
- https://access.redhat.com/errata/RHSA-2026:54435
- https://access.redhat.com/errata/RHSA-2026:53806
- https://access.redhat.com/errata/RHSA-2026:53646
- https://access.redhat.com/errata/RHSA-2026:53645
- https://access.redhat.com/errata/RHSA-2026:53644
- https://access.redhat.com/errata/RHSA-2026:50085
- https://access.redhat.com/errata/RHSA-2026:49701
- https://access.redhat.com/errata/RHSA-2026:49700
- https://access.redhat.com/errata/RHSA-2026:48151
- https://access.redhat.com/errata/RHSA-2026:41951
- https://access.redhat.com/errata/RHSA-2026:37390
- https://access.redhat.com/errata/RHSA-2026:34608
- https://access.redhat.com/errata/RHSA-2026:26586
- https://access.redhat.com/errata/RHSA-2026:26018
- https://access.redhat.com/errata/RHSA-2026:26017
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N- Weakness (CWE)
CWE-345, CWE-346- Platform
- Java / Kotlin (Maven)
- Package
io.netty:netty-resolver-dns- Disclosed
- 08.06.2026
- Updated
- 11.10.2026 13:20
Sources and licenses
OSV / GitHub Advisory Database - GHSA-676x-f7gg-47vc - CC BY 4.0
Vulnerability history: io.netty:netty-resolver-dns
All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 06.2026 06.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 2
- Medium 1
Disclosures per year
- 2026: 3
-
Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records this entry
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