Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, a remote unauthenticated peer can leak one direct `ByteBuf` per HTTP/2 `DATA` frame in applications that enable HTTP/2 content decompression via `DelegatingDecompressorFrameListener`. When a `DATA` frame is processed for a stream whose decompressor has already been closed, `Http2Decompressor.decompress(...)` calls `decompressor.writeInbound(data.retain())` and does not release the retained buffer on the error path, eventually exhausting direct memory and crashing the JVM. 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 None

Availability Impact High

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
>= 4.2.0.Final, < 4.2.16.Final affected —
>= 4.1.0.Final, < 4.1.136.Final affected —

No data.

No data.

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bhttps://github.com/netty/netty/releases/tag/netty-4.2.16.Final cve-icon
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6 cve-icon
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final cve-icon
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final cve-icon
https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972 cve-icon
History

Wed, 22 Jul 2026 05:30:00 +0000

Type Values Removed Values Added
First Time appeared Netty
Netty netty
Vendors & Products Netty
Netty netty

Tue, 21 Jul 2026 22:30:00 +0000

Type Values Removed Values Added
Description Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, a remote unauthenticated peer can leak one direct `ByteBuf` per HTTP/2 `DATA` frame in applications that enable HTTP/2 content decompression via `DelegatingDecompressorFrameListener`. When a `DATA` frame is processed for a stream whose decompressor has already been closed, `Http2Decompressor.decompress(...)` calls `decompressor.writeInbound(data.retain())` and does not release the retained buffer on the error path, eventually exhausting direct memory and crashing the JVM. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Title Netty: HTTP/2 decompression leaks ByteBuf reference count when the decompressor channel is already closed (Direct memory leak / OOM DoS)
Weaknesses CWE-400
CWE-401
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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-21T22:11:17.470Z

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

Link: CVE-2026-56819

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-22T05:15:02Z

Weaknesses