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TI-2026-42714 Aliases CVE-2026-59900GHSA-c69g-56f8-xwqj

Netty codec-http2: Lack of Host Header Deduplication in HTTP/2→HTTP/1.x Translation Leads to Request Routing Bypass

Priority LOW 37CWE-444Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Partial Red Hat: 2 fixed, 19 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (`Http2StreamFrameToHttpObjectCodec` and `InboundHttp2ToHttpAdapter`) fails to deduplicate or validate `Host` headers when an HTTP/2 client supplies both the `:authority` pseudo-header and a literal `host` header in a single HEADERS frame. The translator maps `:authority` to `Host` and separately copies the literal `host` header, producing an `HttpRequest` object containing two `Host` headers with attacker-controlled differing values. This issue has been 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 0.00398 34th percentileScored 2026-11-07
Fix Partial netty (netty): 4.2.16.Final, 4.1.136.Finalio.netty:netty-codec-http2 (Maven): 4.2.16.Final, 4.1.136.FinalRed Hat: 2 advisoriesRed Hat: 2 fixed, 19 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; before 4.1.136.Final4.2.16.Final, 4.1.136.FinalPatch availableCNA
—io.netty:netty-codec-http2 (Maven)4.2.0.Final to before 4.2.16.Final4.2.16.FinalPatch availableGHSA-c69g-56f8-xwqj
—io.netty:netty-codec-http2 (Maven)before 4.1.136.Final4.1.136.FinalPatch availableGHSA-c69g-56f8-xwqj
  • netty Vendornetty Affected 4.2.0.Final to before 4.2.16.Final; before 4.1.136.Final Fixed in 4.2.16.Final, 4.1.136.Final Patch available CNA
  • io.netty:netty-codec-http2 (Maven) Vendor— Affected 4.2.0.Final to before 4.2.16.Final Fixed in 4.2.16.Final Patch available GHSA-c69g-56f8-xwqj
  • io.netty:netty-codec-http2 (Maven) Vendor— Affected before 4.1.136.Final Fixed in 4.1.136.Final Patch available GHSA-c69g-56f8-xwqj

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*before 4.1.136; 4.2.0 to before 4.2.16Vulnerablenetty
  • cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* Versions 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-c69g-56f8-xwqj io.netty:netty-codec-http2 (Maven) Fixed in 4.2.16.Final Advisory →
  • Fix · GHSA-c69g-56f8-xwqj io.netty:netty-codec-http2 (Maven) Fixed in 4.1.136.Final Advisory →

Red Hat 2 advisories

  • 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: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Cryostat 4AffectedNo fix yet: Fix deferred
OpenShift ServerlessAffectedNo fix yet: Fix deferred
Red Hat AMQ Broker 7AffectedNo fix yet: Fix deferred
Red Hat Build of KeycloakAffectedNo fix yet: Fix deferred
Red Hat Data Grid 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix yet: Fix deferred
Red Hat JBoss Enterprise Application Platform 7AffectedNo fix planned: Out of support scope
Red Hat JBoss Enterprise Application Platform Expansion PackAffectedNo fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred
Red Hat Single Sign-On 7AffectedNo fix planned: Out of support scope
Red Hat build of Apache Camel - HawtIO 4AffectedNo fix yet: Fix deferred
Red Hat build of Apache Camel 4 for Quarkus 3AffectedNo fix yet: Fix deferred
Red Hat build of Apache Camel for Spring Boot 4AffectedNo fix yet: Fix deferred
Red Hat build of Apicurio Registry 3AffectedNo fix yet: Fix deferred
Red Hat build of Debezium 3AffectedNo fix yet: Fix deferred
Red Hat build of QuarkusAffectedNo fix planned: Out of support scope
streams for Apache Kafka 2AffectedNo fix planned: Out of support scope
streams for Apache Kafka 3AffectedNo fix yet: Fix deferred
Red Hat build of Quarkus 3.27.4.SP3Fixed RHSA-2026:47189
Red Hat build of Quarkus 3.33.2.SP3Fixed RHSA-2026:47172
Not affected: 2 products
  • Red Hat build of Quarkus 3.27.4.SP3
  • Red Hat build of Quarkus 3.33.2.SP3

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-59900
  2. 2026-10-03 Alias added: GHSA-c69g-56f8-xwqj
  3. 2026-10-20 Affected versions changed · Red Hat

References

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