GHSA-676x-f7gg-47vc — netty-resolver-dns
HIGHGHSA-676x-f7gg-47vc is a high-severity (CVSS 8.7) CWE-345 vulnerability in io.netty:netty-resolver-dns. A fix is available for io.netty:netty-resolver-dns — see the affected versions and patch details below.
Netty Vulnerable to DNS Cache Poisoning via Missing Bailiwick Checks in CNAME Records
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-676x-f7gg-47vc.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-676x-f7gg-47vc plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
io.netty:netty-resolver-dns☕io.netty:netty-resolver-dnsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-resolver-dns | ≥ 4.2.0.Final&&< 4.2.15.Final | 4.2.15.Finalio.netty:netty-resolver-dns:4.2.15.Final |
| ☕Maven | io.netty:netty-resolver-dns | all versions | 4.1.135.Finalio.netty:netty-resolver-dns:4.1.135.Final |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-resolver-dns, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty:netty-resolver-dns to 4.2.15.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-676x-f7gg-47vc is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-676x-f7gg-47vc can be triaged on real exposure rather than presence alone.
Tailored to GHSA-676x-f7gg-47vc. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Important severity flaw in Netty's DnsResolveContext allows a remote attacker to achieve information disclosure or data manipulation. By crafting malicious DNS responses, an attacker could redirect network traffic or intercept sensitive data, impacting applications utilizing Netty for DNS resolution in Red Hat…
| Product | Fixed in | Advisory |
|---|---|---|
| Cryostat 4 on RHEL 9 | cryostat/cryostat-reports-rhel9:4.2.0-13 | RHSA-2026:48151 |
| Red Hat Build of Apache Camel 3.33 for Quarkus 3.33.2.SP1 | netty-resolver-dns | RHSA-2026:26586 |
| Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16 | netty-resolver-dns | RHSA-2026:37390 |
| Red Hat build of Quarkus 3.27.4.SP1 | netty-resolver-dns | RHSA-2026:26018 |
| Red Hat build of Quarkus 3.33.2.SP1 | netty-resolver-dns | RHSA-2026:26017 |
| Red Hat Data Grid 8.6.2 | netty-resolver-dns | RHSA-2026:41951 |
| Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7 | eap7-activemq-artemis-0:2.16.0-22.redhat_00057.1.el7eap | RHSA-2026:53644 |
| Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8 | eap7-activemq-artemis-0:2.16.0-22.redhat_00057.1.el8eap | RHSA-2026:53645 |
Frequently Asked Questions
Is GHSA-676x-f7gg-47vc in your dependencies?
O3 Security finds GHSA-676x-f7gg-47vc across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.