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Fencer Intel
medium 6.8

CVE-2026-45673 json

Netty: DNS Cache Poisoning due to Predictable PRNG and Default Static Source Port

published 5mo ago modified last mo. also EUVD-2026-36445 , GHSA-xmv7-r254-6q78

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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 DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack). Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Patch / fix

  • maven io.netty:netty-resolver-dns 4.1.135.Final, 4.2.15.Final
  • io.netty netty-resolver-dns 4.1.135.Final, 4.2.15.Final
  • netty netty 4.1.135.Final, 4.2.15.Final
  • netty-tcnative SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.0.79-150200.3.45.1
  • netty SLE Module for Package Hub 15 SP7 4.1.135-150200.4.50.1

suse advisories SUSE-SU-2026:2802-1

  • netty openSUSE Tumbleweed 4.1.135-1.1

opensuse advisories openSUSE-SU-2026:11033-1

Is CVE-2026-45673 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-45673 updated cvss 6.8

netty-resolver-dns: Netty DNS resolver: DNS Cache Poisoning via predictable transaction IDs

  • Red Hat Cryostat 4 netty-resolver-dns Red Hat OpenShift Serverless openshift-serverless-1/kn-ekb-receiver-rhel9, openshift-serverless-1/kn-ekb-dispatcher-rhel9, openshift-serverless-1/kn-eventing-integrations-log-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sns-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sqs-sink-rhel9, +4 more Red Hat build of Apache Camel - HawtIO 4 netty-resolver-dns Red Hat build of Apache Camel 4 for Quarkus 3 netty-resolver-dns Red Hat build of Apache Camel for Spring Boot 4 netty-resolver-dns Red Hat build of Apicurio Registry 3 netty-resolver-dns
    +13 more products
    Red Hat build of Debezium 3 netty-resolver-dns Red Hat Build of Keycloak netty-resolver-dns, rhbk-rhel9-operator, rhbk/keycloak-rhel9, rhbk-openshift-rhel9, rhbk/keycloak-rhel9-operator Red Hat Data Grid 8 netty-resolver-dns Red Hat Enterprise Linux AI (RHEL AI) 3 bazel6, bazel7, bazel8 Red Hat Fuse 7 netty-resolver-dns Red Hat JBoss Enterprise Application Platform 7 netty-resolver-dns Red Hat JBoss Enterprise Application Platform 8 netty-resolver-dns Red Hat JBoss Enterprise Application Platform Expansion Pack netty-resolver-dns Red Hat OpenShift AI (RHOAI) rhoai/odh-spark-operator-rhel9, rhoai/odh-trustyai-service-rhel9, rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch210-py312-rhel9, +1 more Red Hat OpenShift Dev Spaces devspaces/server-rhel9, devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9, devspaces/multicluster-redirector-rhel9 Red Hat Single Sign-On 7 netty-resolver-dns Red Hat streams for Apache Kafka 2 netty-resolver-dns Red Hat streams for Apache Kafka 3 netty-resolver-dns
    affected: workaround, no fix available “Fix deferred”
  • Red Hat build of Quarkus 3.27.4.SP1 netty-resolver-dns 4.1.135.Final-redhat-00001
    fixed: vendor fix RHSA-2026:26018
  • Red Hat build of Quarkus 3.33.2.SP1 netty-resolver-dns 4.1.135.Final-redhat-00001
    fixed: vendor fix RHSA-2026:26017
  • Red Hat build of Quarkus 3.27.4.SP1 jna 5.8.0, db2 1.21.4, h2 2.3.230, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1009 more Red Hat build of Quarkus 3.33.2.SP1 jna 5.8.0, bson 5.6.4, h2 2.4.240, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1018 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
GitHub 3.1 6.8 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
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

Affected products

  • netty netty

Classification

Weakness
  • CWE-330 Use of Insufficiently Random Values
  • CWE-340 Generation of Predictable Numbers or Identifiers

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.