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TI-2026-40300 Aliases CVE-2026-55833GHSA-mvh2-crg5-v77c

Netty SPDY zlib header block continues decoded expansion after maxHeaderSize truncation

Priority MEDIUM 40CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 19 fixed, 10 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty SPDY header decoding continues inflating zlib-compressed header blocks after the raw header parser has exceeded `maxHeaderSize` and marked the frame truncated in `SpdyFrameCodec`, allowing a remote peer to send a small compressed `HEADERS` block that expands into much larger raw header data and causes compression-amplified CPU and allocation churn. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00665 52nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial netty (netty): 4.2.16.Final, 4.1.136.Finalio.netty:netty-codec-http (Maven): 4.2.16.Final, 4.1.136.FinalRed Hat: 21 advisoriesRed Hat: 19 fixed, 10 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
nettynetty4.2.0.Final to before 4.2.16.Final; 4.1.0.Final to before 4.1.136.Final4.2.16.Final, 4.1.136.FinalPatch availableCNA
—io.netty:netty-codec-http (Maven)4.2.0.Final to before 4.2.16.Final4.2.16.FinalPatch availableGHSA-mvh2-crg5-v77c
—io.netty:netty-codec-http (Maven)4.1.0.Final to before 4.1.136.Final4.1.136.FinalPatch availableGHSA-mvh2-crg5-v77c
  • netty Vendornetty Affected 4.2.0.Final to before 4.2.16.Final; 4.1.0.Final to before 4.1.136.Final Fixed in 4.2.16.Final, 4.1.136.Final Patch available CNA
  • io.netty:netty-codec-http (Maven) Vendor— Affected 4.2.0.Final to before 4.2.16.Final Fixed in 4.2.16.Final Patch available GHSA-mvh2-crg5-v77c
  • io.netty:netty-codec-http (Maven) Vendor— Affected 4.1.0.Final to before 4.1.136.Final Fixed in 4.1.136.Final Patch available GHSA-mvh2-crg5-v77c

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*4.1.0 to before 4.1.136; 4.2.0 to before 4.2.16Vulnerablenetty
  • cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* Versions 4.1.0 to before 4.1.136; 4.2.0 to before 4.2.16 Vulnerable ·netty

Remediation

  • Fix · CNA netty (netty) Fixed in 4.2.16.Final, 4.1.136.Final
  • Fix · GHSA-mvh2-crg5-v77c io.netty:netty-codec-http (Maven) Fixed in 4.2.16.Final Advisory →
  • Fix · GHSA-mvh2-crg5-v77c io.netty:netty-codec-http (Maven) Fixed in 4.1.136.Final Advisory →

Red Hat 21 advisories

  • RHSA-2026:90321 Released 2026-10-26 · Red Hat rating Critical
    Red Hat OpenShift Dev Spaces 3.31.0 Release.
    • Red Hat OpenShift Dev Spaces 3.31 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/jetbrains-ide-rhel9 +8
  • RHSA-2026:87410 Released 2026-10-21 · Red Hat rating Critical
    RHOAI 2.25.12 - 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-nlp-rhel9, registry.redhat.io/rhoai/odh-codeflare-operator-rhel9 +47
  • RHSA-2026:84734 Released 2026-10-19 · Red Hat rating Critical
    RHOAI 3.4.5 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 3.4 registry.redhat.io/rhoai/odh-ai-gateway-payload-processing-rhel9, registry.redhat.io/rhoai/odh-automl-rhel9, registry.redhat.io/rhoai/odh-autorag-rhel9 +47
Show 18 more Red Hat advisories
  • RHSA-2026:76637 Released 2026-10-06 · Red Hat rating Important
    Apicurio Registry (container images) release and security update [ 3.3.3 GA ]
    • Red Hat build of Apicurio Registry 3.3.3
  • RHSA-2026:70277 Released 2026-09-22 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.8 security update
    • Red Hat JBoss Enterprise Application Platform 8.1.8.GA com.fasterxml.jackson.core.jackson-core-2.18.9.redhat-00003.jar, com.fasterxml.jackson.core.jackson-databind-2.18.9.redhat-00003.jar, io.netty.netty-codec-4.1.136.Final-redhat-00001.jar +17
  • RHSA-2026:70230 Released 2026-09-22 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.8 security update
    • Red Hat JBoss EAP 8.1 for RHEL 10 eap8-activemq-artemis-2.40.0-8.redhat_00024.1.el10eap, eap8-activemq-artemis-cli-2.40.0-8.redhat_00024.1.el10eap, eap8-activemq-artemis-commons-2.40.0-8.redhat_00024.1.el10eap +47
  • RHSA-2026:70228 Released 2026-09-22 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.8 security update
    • Red Hat JBoss EAP 8.1 for RHEL 8 eap8-activemq-artemis-2.40.0-8.redhat_00024.1.el8eap, eap8-activemq-artemis-cli-2.40.0-8.redhat_00024.1.el8eap, eap8-activemq-artemis-commons-2.40.0-8.redhat_00024.1.el8eap +47
  • RHSA-2026:70229 Released 2026-09-22 · Red Hat rating Important
    Red Hat JBoss Enterprise Application Platform 8.1.8 security update
    • Red Hat JBoss EAP 8.1 for RHEL 9 eap8-activemq-artemis-2.40.0-8.redhat_00024.1.el9eap, eap8-activemq-artemis-cli-2.40.0-8.redhat_00024.1.el9eap, eap8-activemq-artemis-commons-2.40.0-8.redhat_00024.1.el9eap +47
  • RHSA-2026:69296 Released 2026-09-21 · Red Hat rating Important
    Red Hat Data Grid 8.6.3 security update
    • Red Hat Data Grid 8.6.3
  • RHSA-2026:68754 Released 2026-09-17 · Red Hat rating Important
    Red Hat OpenShift Dev Spaces 3.30.1 Release.
    • Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/openvsx-rhel9 +2
  • RHSA-2026:68333 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Cryostat security update
    • Cryostat 4 on RHEL 9 cryostat/cryostat-agent-init-rhel9, cryostat/cryostat-grafana-dashboard-rhel9, cryostat/cryostat-openshift-console-plugin-rhel9 +5
  • RHSA-2026:66545 Released 2026-09-10 · Red Hat rating Important
    Red Hat AMQ Broker 7.13.6 release and security update
    • Red Hat AMQ Broker 7.13.6
  • RHSA-2026:66488 Released 2026-09-10 · Red Hat rating Important
    Red Hat AMQ Broker 7.14.1 release and security update
    • Red Hat AMQ Broker 7.14.1
  • 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-2026:62260 Released 2026-09-01 · Red Hat rating Important
    Red Hat OpenShift Dev Spaces 3.30.0 Release.
    • Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/configbump-rhel9, registry.redhat.io/devspaces/dashboard-rhel9 +7
  • RHSA-2026:54622 Released 2026-08-13 · Red Hat rating Important
    Red Hat Build of Apache Camel 4.18.3 for Spring Boot release.
    • Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16
  • RHSA-2026:54435 Released 2026-08-12 · Red Hat rating Important
    Streams for Apache Kafka 3.2.1 release and security update
    • Streams for Apache Kafka 3.2.1
  • RHSA-2026:50846 Released 2026-08-05 · Red Hat rating Important
    Red Hat build of Keycloak 26.4.14 Security Update
    • Red Hat build of Keycloak 26.4.14
  • RHSA-2026:50848 Released 2026-08-05 · Red Hat rating Important
    Red Hat build of Keycloak 26.6.5 Security Update
    • Red Hat build of Keycloak 26.6.5
  • RHSA-2026:47172 Released 2026-07-30 · Red Hat rating Important
    Red Hat build of Quarkus 3.33.2.SP3 security update
    • Red Hat build of Quarkus 3.33.2.SP3 io.netty.netty-codec-haproxy-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.136.Final-redhat-00001.jar +3
  • RHSA-2026:47189 Released 2026-07-29 · Red Hat rating Important
    Red Hat build of Quarkus 3.27.4.SP3 security update
    • Red Hat build of Quarkus 3.27.4.SP3 io.netty.netty-codec-haproxy-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http-4.1.136.Final-redhat-00001.jar, io.netty.netty-codec-http2-4.1.136.Final-redhat-00001.jar +3

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
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 JBoss Enterprise Application Platform 7AffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat Single Sign-On 7AffectedNo fix yet: Fix deferred
Red Hat build of Apache Camel - HawtIO 4AffectedNo fix yet
Red Hat build of Debezium 3AffectedNo fix planned: Will not fix
Red Hat build of QuarkusAffectedNo fix yet: Fix deferred
Cryostat 4 on RHEL 9Fixed RHSA-2026:68333
Red Hat AMQ Broker 7.13.6Fixed RHSA-2026:66545
Red Hat AMQ Broker 7.14.1Fixed RHSA-2026:66488
Red Hat Data Grid 8.6.3Fixed RHSA-2026:69296
Red Hat JBoss EAP 8.1 for RHEL 10Fixed RHSA-2026:70230
Red Hat JBoss EAP 8.1 for RHEL 8Fixed RHSA-2026:70228
Red Hat JBoss EAP 8.1 for RHEL 9Fixed RHSA-2026:70229
Red Hat JBoss Enterprise Application Platform 8.1.8.GAFixed RHSA-2026:70277
Red Hat OpenShift AI 2.25Fixed RHSA-2026:65126, RHSA-2026:87410
Red Hat OpenShift AI 3.4Fixed RHSA-2026:84734
Red Hat OpenShift Dev Spaces 3.30Fixed RHSA-2026:62260, RHSA-2026:68754
Red Hat OpenShift Dev Spaces 3.31Fixed RHSA-2026:90321
Red Hat build of Apache Camel 4.18.3 for Spring Boot 3.5.16Fixed RHSA-2026:54622
Red Hat build of Apicurio Registry 3.3.3Fixed RHSA-2026:76637
Red Hat build of Keycloak 26.4.14Fixed RHSA-2026:50846
Red Hat build of Keycloak 26.6.5Fixed RHSA-2026:50848
Red Hat build of Quarkus 3.27.4.SP3Fixed RHSA-2026:47189
Red Hat build of Quarkus 3.33.2.SP3Fixed RHSA-2026:47172
Streams for Apache Kafka 3.2.1Fixed RHSA-2026:54435
Not affected: 13 products
  • Cryostat 4 on RHEL 9
  • Red Hat JBoss Enterprise Application Platform 8.1.8.GA
  • Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 2.25
  • Red Hat OpenShift AI 3.4
  • Red Hat OpenShift Dev Spaces 3.30
  • Red Hat OpenShift Dev Spaces 3.31
  • Red Hat Satellite 6
  • Red Hat build of Apache Camel 4 for Quarkus 3
  • Red Hat build of Quarkus 3.27.4.SP3
  • Red Hat build of Quarkus 3.33.2.SP3
  • streams for Apache Kafka 2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55833
  2. 2026-10-03 Alias added: GHSA-mvh2-crg5-v77c
  3. 2026-10-06 Affected versions changed · Red Hat
  4. 2026-10-09 Fix available: RHSA-2026:76637 · Red Hat
  5. 2026-10-09 Fix available: RHSA-2026:70277 · Red Hat
  6. 2026-10-09 Fix available: Red Hat JBoss Enterprise Application Platform 8.1, Red Hat build of Apicurio Registry 3.3.3 · Red Hat
  7. 2026-10-20 Fix available: RHSA-2026:84734 · Red Hat
  8. 2026-10-20 Fix available: Red Hat OpenShift AI 3.4 · Red Hat
  9. 2026-10-21 Fix available: Red Hat JBoss Enterprise Application Platform 8.1.8.GA · Red Hat
  10. 2026-10-22 Fix available: RHSA-2026:87410 · Red Hat
  11. 2026-10-23 Fix available: RHSA-2026:50846 · Red Hat
  12. 2026-10-23 Fix available: RHSA-2026:50848 · Red Hat
  13. 2026-10-23 Fix available: Red Hat build of Keycloak 26.4.14, Red Hat build of Keycloak 26.6.5 · Red Hat
  14. 2026-10-29 Fix available: Red Hat OpenShift Dev Spaces 3.31 · Red Hat
  15. 2026-10-30 Fix available: RHSA-2026:90321 · Red Hat
  16. 2026-11-03 Affected versions changed · Red Hat

References

Exploit 1

Patch 2

Advisory 1

Other 3

  • 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