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TI-2026-40971 Aliases CVE-2026-56818GHSA-p9jm-q85p-7mcp

Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state

Priority HIGH 68CWE-401Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · Low · Low
Fix status
Partial Red Hat: 5 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-401.

Summary

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, the RedisArrayAggregator Redis codec clears retained partial aggregate state when the maxNestedArrayDepth limit is exceeded, but it does not clear the same state when the sibling maxElements limit is exceeded. A peer can start a valid RESP array, send a bulk string child, then send a nested array header longer than the configured maxElements. Netty throws a decoder exception in decodeRedisArrayHeader, but the existing partial aggregate remains retained in the handler. If the application leaves the channel alive after the exception, later messages are still consumed into the pre-error aggregate, allowing an unauthenticated peer to keep attacker-controlled aggregate state alive across a security-limit exception and pin retained pooled buffers. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00473 41st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial netty (netty): 4.1.136.Final, 4.2.16.Finalio.netty:netty-codec-redis (Maven): 4.1.136.Final, 4.2.16.FinalRed Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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 4.1.136.Final; 4.2.0-Final to before 4.2.16.Final4.1.136.Final, 4.2.16.FinalPatch availableCNA
—io.netty:netty-codec-redis (Maven)before 4.1.136.Final4.1.136.FinalPatch availableGHSA-p9jm-q85p-7mcp
—io.netty:netty-codec-redis (Maven)4.2.0-Final to before 4.2.16.Final4.2.16.FinalPatch availableGHSA-p9jm-q85p-7mcp
  • netty Vendornetty Affected before 4.1.136.Final; 4.2.0-Final to before 4.2.16.Final Fixed in 4.1.136.Final, 4.2.16.Final Patch available CNA
  • io.netty:netty-codec-redis (Maven) Vendor— Affected before 4.1.136.Final Fixed in 4.1.136.Final Patch available GHSA-p9jm-q85p-7mcp
  • io.netty:netty-codec-redis (Maven) Vendor— Affected 4.2.0-Final to before 4.2.16.Final Fixed in 4.2.16.Final Patch available GHSA-p9jm-q85p-7mcp

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 4.1.136.Final, 4.2.16.Final
  • Fix · GHSA-p9jm-q85p-7mcp io.netty:netty-codec-redis (Maven) Fixed in 4.1.136.Final Advisory →
  • Fix · GHSA-p9jm-q85p-7mcp io.netty:netty-codec-redis (Maven) Fixed in 4.2.16.Final Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Data Grid 8AffectedNo 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 Single Sign-On 7AffectedNo fix planned: Out of support scope
Red Hat build of Apache Camel for Spring Boot 4AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56818
  2. 2026-10-03 Alias added: GHSA-p9jm-q85p-7mcp

References

Exploit 1

Patch 3

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