Netty: Prior to versions 4.1.136.Final and 4.2.16.Final, HttpContentEncoder (the superclass of the production handler HttpContentCompressor) maintains a… (CVE-2026-59899)
Description
Netty versions prior to 4.1.136.Final and 4.2.16.Final contain a resource exhaustion vulnerability in the HttpContentEncoder class. This vulnerability allows an attacker to flood a connection with HTTP/1.1 pipelined requests faster than responses are produced, causing an unbounded queue to accumulate attacker-controlled data per channel. The issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
CVSS v3.1
Score 7.5high
Affected software
pkg:deb/ubuntu/netty?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/netty?arch=source&distro=esm-apps-legacy/xenialpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/netty?arch=source&distro=stonkingpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-59899 is a resource exhaustion vulnerability in Netty's HttpContentEncoder class present in versions prior to 4.1.136.Final and 4.2.16.Final. The class maintains an unbounded queue for each channel that accumulates attacker-controlled data. An attacker can exploit this via HTTP/1.1 pipelining to flood the connection with requests faster than the server can respond, leading to resource exhaustion. The vulnerability has been addressed in the specified fixed versions.
Potential Impact
Successful exploitation can cause resource exhaustion on the affected server, potentially leading to denial of service conditions. There is no impact on confidentiality or integrity reported. The CVSS score is 7.5 (medium severity) with the impact vector indicating no confidentiality or integrity loss but high availability impact.
Mitigation Recommendations
Upgrade to Netty versions 4.1.136.Final or 4.2.16.Final or later where this vulnerability is fixed. No other mitigations are specified or recommended by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-q4f6-jm68-57ww
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-59899"]
- Ecosystems
- ["Maven"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6a6150d39c2644c7f8da06e4
Added to database: 07/22/2026, 23:22:59 UTC
Last enriched: 10/18/2026, 04:35:14 UTC
Last updated: 10/21/2026, 13:20:22 UTC
Views: 126
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