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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
netty netty affected
Version Status Constraints
< 4.1.136.Final affected —
>= 4.2.0-Final, < 4.2.16.Final affected —

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Project Subscriptions

No data.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-p9jm-q85p-7mcp Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b cve-icon
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 cve-icon
https://github.com/netty/netty/pull/17065 cve-icon
https://github.com/netty/netty/security/advisories/GHSA-p9jm-q85p-7mcp cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-56818 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-56818 cve-icon
History

Fri, 07 Aug 2026 17:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in the Netty `netty-codec-redis` component. This vulnerability allows a remote attacker to cause a denial of service (DoS) by sending specially crafted Redis protocol frames over long-lived connections. The Redis decoder fails to properly release allocated memory, leading to memory exhaustion and application instability. 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.
Title io.netty/netty-codec-redis: Netty: Memory leak in netty-codec-redis Netty: RedisArrayAggregator max-elements failure leaves retained partial aggregate state
Weaknesses CWE-401
CWE-703
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'}

Tue, 28 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in the Netty `netty-codec-redis` component. This vulnerability allows a remote attacker to cause a denial of service (DoS) by sending specially crafted Redis protocol frames over long-lived connections. The Redis decoder fails to properly release allocated memory, leading to memory exhaustion and application instability.
Title io.netty/netty-codec-redis: Netty: Memory leak in netty-codec-redis
Weaknesses CWE-772
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-07T17:14:02.356Z

Reserved: 2026-06-23T14:55:09.116Z

Link: CVE-2026-56818

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Important

Publid Date: 2026-07-09T00:00:00Z

Links: CVE-2026-56818 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses