Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-56818

CVE-2026-56818MEDIUM

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  L  L    6.5   .0047   38.7     —

AFFECTED
  Product  Versions           Fixed
  netty    < 4.1.136.Final –  —

TIMELINE
  Jun 23  Reserved by GitHub_M
  Aug 7   Published (CNA: GitHub_M)
  Sep 23  EXPLOIT PUBLISHED — CVE-2026-56818 (netty). Public exploit reference added.

CWE-401, CWE-703 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Analyzed

Description

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 23, 2026	Reserved	Reserved by GitHub_M
August 7, 2026	Published	Published (CNA: GitHub_M)
September 23, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-56818 (netty). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
netty	netty	—	< 4.1.136.Final	—

Weaknesses

CWE-401 · CWE-703

References (4)

https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b [Patch]
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 [Patch]
https://github.com/netty/netty/pull/17065 [Issue Tracking, Patch]
https://github.com/netty/netty/security/advisories/GHSA-p9jm-q85p-7mcp [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-56818 at cve.org

Vendors: netty

Weaknesses: CWE-401 · CWE-703

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-56818 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.