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TI-2026-26232 Aliases CVE-2026-33871GHSA-w9fj-cfpg-grvv

Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass

Priority MEDIUM 46CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 17 fixed, 21 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.

Summary

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of `CONTINUATION` frames. The server's lack of a limit on the number of `CONTINUATION` frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01145 66th percentileScored 2026-11-07
Fix Partial netty (netty): 4.1.132.Final, 4.2.10.Finalio.netty:netty-codec-http2 (Maven): 4.1.132.Final, 4.2.11.FinalRed Hat: 18 advisoriesRed Hat: 17 fixed, 21 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nettynettybefore 4.1.132.Final; 4.2.0.Alpha1 to before 4.2.10.Final4.1.132.Final, 4.2.10.FinalPatch availableCNA
—io.netty:netty-codec-http2 (Maven)before 4.1.132.Final4.1.132.FinalPatch availableGHSA-w9fj-cfpg-grvv
—io.netty:netty-codec-http2 (Maven)4.2.0.Alpha1 to before 4.2.11.Final4.2.11.FinalPatch availableGHSA-w9fj-cfpg-grvv
  • netty Vendornetty Affected before 4.1.132.Final; 4.2.0.Alpha1 to before 4.2.10.Final Fixed in 4.1.132.Final, 4.2.10.Final Patch available CNA
  • io.netty:netty-codec-http2 (Maven) Vendor— Affected before 4.1.132.Final Fixed in 4.1.132.Final Patch available GHSA-w9fj-cfpg-grvv
  • io.netty:netty-codec-http2 (Maven) Vendor— Affected 4.2.0.Alpha1 to before 4.2.11.Final Fixed in 4.2.11.Final Patch available GHSA-w9fj-cfpg-grvv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*before 4.1.132; 4.2.0 to before 4.2.10Vulnerablenetty
  • cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* Versions before 4.1.132; 4.2.0 to before 4.2.10 Vulnerable ·netty

Remediation

  • Fix · CNA netty (netty) Fixed in 4.1.132.Final, 4.2.10.Final
  • Fix · GHSA-w9fj-cfpg-grvv io.netty:netty-codec-http2 (Maven) Fixed in 4.1.132.Final Advisory →
  • Fix · GHSA-w9fj-cfpg-grvv io.netty:netty-codec-http2 (Maven) Fixed in 4.2.11.Final Advisory →

Red Hat 18 advisories

  • RHSA-2026:65126 Released 2026-09-08 · Red Hat rating Important
    RHOAI 2.25.11 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-built-in-detector-rhel9, registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47
  • RHSA-2026:34608 Released 2026-07-02 · Red Hat rating Important
    Streams for Apache Kafka 2.9.4 release and security update
    • Streams for Apache Kafka 2.9.4
  • RHSA-2026:22619 Released 2026-06-02 · Red Hat rating Important
    Red Hat Data Grid 8.6.1 security update
    • Red Hat Data Grid 8.6.1
Show 15 more Red Hat advisories
  • RHSA-2026:17789 Released 2026-05-26 · Red Hat rating Important
    Red Hat build of Cryostat 4.2.0: new RHEL 9 container image security update
    • Cryostat 4 on RHEL 9 cryostat/cryostat-grafana-dashboard-rhel9, cryostat/cryostat-openshift-console-plugin-rhel9, cryostat/cryostat-reports-rhel9 +4
  • RHSA-2026:19678 Released 2026-05-20 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.6 XP 6.0.4.GA security release
    • Red Hat JBoss Enterprise Application Platform 6.0.4.GA io.netty.netty-codec-http2-4.1.132.Final-redhat-00001.jar, org.apache.zookeeper.zookeeper-3.8.6.redhat-00001.jar
  • RHSA-2026:18054 Released 2026-05-18 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.6 security update
    • Red Hat JBoss EAP 8.1 for RHEL 8 eap8-activemq-artemis-2.40.0-6.redhat_00012.1.el8eap, eap8-activemq-artemis-cli-2.40.0-6.redhat_00012.1.el8eap, eap8-activemq-artemis-commons-2.40.0-6.redhat_00012.1.el8eap +47
  • RHSA-2026:18055 Released 2026-05-18 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.6 security update
    • Red Hat JBoss EAP 8.1 for RHEL 9 eap8-activemq-artemis-2.40.0-6.redhat_00012.1.el9eap, eap8-activemq-artemis-cli-2.40.0-6.redhat_00012.1.el9eap, eap8-activemq-artemis-commons-2.40.0-6.redhat_00012.1.el9eap +47
  • RHSA-2026:18059 Released 2026-05-18 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.6 security update
    • Red Hat JBoss Enterprise Application Platform 8.1.6.GA io.netty.netty-codec-http-4.1.132.Final-redhat-00001.jar, org.apache.activemq.artemis-server-2.40.0.redhat-00012.jar, org.bouncycastle.bcpkix-jdk18on-1.84.0.redhat-00001.jar +7
  • RHSA-2026:17668 Released 2026-05-14 · Red Hat rating Critical
    Red Hat Build of Apache Camel 4.18.1 for Spring Boot release.
    • Red Hat build of Apache Camel 4.18.1 for Spring Boot 3.5.14
  • RHSA-2026:14276 Released 2026-05-06 · Red Hat rating Important
    Red Hat AMQ Broker 7.12.7 release and security update
    • Red Hat AMQ Broker 7.12.7
  • RHSA-2026:14272 Released 2026-05-06 · Red Hat rating Important
    Red Hat AMQ Broker 7.13.5 release and security update
    • Red Hat AMQ Broker 7.13.5
  • RHSA-2026:13571 Released 2026-05-04 · Red Hat rating Critical
    Streams for Apache Kafka 3.2.0 release and security update
    • Streams for Apache Kafka 3.2.0
  • RHSA-2026:10184 Released 2026-04-23 · Red Hat rating Important
    RHOAI 2.25.5 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-caikit-nlp-rhel9, registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +47
  • RHSA-2026:10175 Released 2026-04-23 · Red Hat rating Important
    Red Hat OpenShift Dev Spaces 3.27.1 Release.
    • Red Hat OpenShift Dev Spaces 3.27 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/devspaces-rhel9-operator +8
  • RHSA-2026:8509 Released 2026-04-16 · Red Hat rating Important
    Red Hat AMQ Broker 7.14.0 release and security update
    • Red Hat AMQ Broker 7.14.0
  • RHSA-2026:8159 Released 2026-04-14 · Red Hat rating Important
    Red Hat Build of Apache Camel 4.14 for Quarkus 3.27 update is now available (RHBQ 3.27.3.GA)
    • Red Hat Build of Apache Camel 3.27.1.SP1 io.netty.netty-codec-http-4.1.128.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.128.Final-redhat-00001.jar, io.vertx.vertx-core-4.5.22.redhat-00001.jar
  • RHSA-2026:7109 Released 2026-04-14 · Red Hat rating Important
    Red Hat build of Quarkus 3.20.6 release and security update
    • Red Hat build of Quarkus 3.20.6.redhat io.netty.netty-codec-http-4.1.132.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.132.Final-redhat-00001.jar, io.vertx.vertx-core-4.5.26.redhat-00001.jar +2
  • RHSA-2026:7380 Released 2026-04-14 · Red Hat rating Important
    Red Hat build of Quarkus 3.27.3 release and security update
    • Red Hat build of Quarkus 3.27.3.redhat io.netty.netty-codec-http-4.1.132.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.132.Final-redhat-00001.jar, io.vertx.vertx-core-4.5.26.redhat-00001.jar +2

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Cryostat 4AffectedNo fix yet
Logging Subsystem for Red Hat OpenShiftAffectedNo fix yet
OpenShift ServerlessAffectedNo fix yet
Red Hat AMQ ClientsAffectedNo fix yet
Red Hat Build of KeycloakAffectedNo fix yet
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet
Red Hat Fuse 7AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Application Platform 7AffectedNo fix planned: Will not fix
Red Hat JBoss Enterprise Application Platform 8AffectedNo fix yet
Red Hat JBoss Enterprise Application Platform Expansion PackAffectedNo fix yet
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat Process Automation 7AffectedNo fix planned: Will not fix
Red Hat Single Sign-On 7AffectedNo fix planned: Will not fix
Red Hat build of Apache Camel - HawtIO 4AffectedNo fix yet
Red Hat build of Apache Camel 4 for Quarkus 3AffectedNo fix yet
Red Hat build of Apicurio Registry 2AffectedNo fix planned: Will not fix
Red Hat build of Apicurio Registry 3AffectedNo fix yet
Red Hat build of Debezium 2AffectedNo fix yet: Fix deferred
Red Hat build of Debezium 3AffectedNo fix planned: Will not fix
Red Hat build of OptaPlanner 8AffectedNo fix planned: Will not fix
Red Hat build of QuarkusAffectedNo fix yet
Cryostat 4 on RHEL 9Fixed RHSA-2026:17789
Red Hat AMQ Broker 7.12.7Fixed RHSA-2026:14276
Red Hat AMQ Broker 7.13.5Fixed RHSA-2026:14272
Red Hat AMQ Broker 7.14.0Fixed RHSA-2026:8509
Red Hat Build of Apache Camel 3.27.1.SP1Fixed RHSA-2026:8159
Red Hat Data Grid 8.6.1Fixed RHSA-2026:22619
Red Hat JBoss EAP 8.1 for RHEL 8Fixed RHSA-2026:18054
Red Hat JBoss EAP 8.1 for RHEL 9Fixed RHSA-2026:18055
Red Hat JBoss Enterprise Application Platform 6.0.4.GAFixed RHSA-2026:19678
Red Hat JBoss Enterprise Application Platform 8.1.6.GAFixed RHSA-2026:18059
Red Hat OpenShift AI 2.25Fixed RHSA-2026:10184, RHSA-2026:65126
Red Hat OpenShift Dev Spaces 3.27Fixed RHSA-2026:10175
Red Hat build of Apache Camel 4.18.1 for Spring Boot 3.5.14Fixed RHSA-2026:17668
Red Hat build of Quarkus 3.20.6.redhatFixed RHSA-2026:7109
Red Hat build of Quarkus 3.27.3.redhatFixed RHSA-2026:7380
Streams for Apache Kafka 2.9.4Fixed RHSA-2026:34608
Streams for Apache Kafka 3.2.0Fixed RHSA-2026:13571
Not affected: 15 products
  • Cryostat 4 on RHEL 9
  • Red Hat Build of Apache Camel 3.27.1.SP1
  • Red Hat JBoss EAP 8.1 for RHEL 8
  • Red Hat JBoss EAP 8.1 for RHEL 9
  • Red Hat JBoss Enterprise Application Platform 6.0.4.GA
  • Red Hat JBoss Enterprise Application Platform 8
  • Red Hat JBoss Enterprise Application Platform 8.1.6.GA
  • Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 2.25
  • Red Hat OpenShift Dev Spaces 3.27
  • Red Hat Satellite 6
  • Red Hat build of Quarkus 3.20.6.redhat
  • Red Hat build of Quarkus 3.27.3.redhat
  • streams for Apache Kafka 3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33871
  2. 2026-10-03 Alias added: GHSA-w9fj-cfpg-grvv
  3. 2026-10-09 Fix available: RHSA-2026:8159 · Red Hat
  4. 2026-10-09 Fix available: RHSA-2026:8509 · Red Hat
  5. 2026-10-09 Fix available: RHSA-2026:14272 · Red Hat
  6. 2026-10-10 Fix available: RHSA-2026:19678 · Red Hat
  7. 2026-10-10 Fix available: Red Hat AMQ Broker 7.13.5, Red Hat AMQ Broker 7.14.0, Red Hat Build of Apache Camel 3.27.1.SP1 +1 · Red Hat
  8. 2026-10-16 Fix available: Red Hat JBoss Enterprise Application Platform 8.1 · Red Hat
  9. 2026-10-20 Fix available: Red Hat JBoss Enterprise Application Platform 8.1.6.GA, Red Hat build of Quarkus 3.20.6.redhat, Red Hat build of Quarkus 3.27.3.redhat · Red Hat

References

Advisory 2

Other 1

  • TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
  • TI-2026-30861 Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization CVSS 3.1CRITICAL 9.8
  • TI-2026-30864 Netty: HttpClientCodec response desynchronization CVSS 3.1CRITICAL 9.1
  • TI-2026-30859 Netty: DNS Codec Input Validation Bypass in Netty (Encoder + Decoder) CVSS 3.1CRITICAL 9.1
  • TI-2026-40973 Netty: Missing CertificateID Validation in OCSP Response Allows Replay Attacks CVSS 3.1CRITICAL 9.1
  • TI-2026-40972 Uncontrolled resource consumption in netty CVSS 3.1HIGH 7.5
See all 92 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences