Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (Http2StreamFrameToHttpObjectCodec and… (CVE-2026-59900)
Description
Netty versions prior to 4.1.136.Final and 4.2.16.Final have a vulnerability in the HTTP/2-to-HTTP/1.x translation layer where both the :authority pseudo-header and a literal Host header can coexist in a single HEADERS frame without proper validation. This leads to an HttpRequest object containing two conflicting Host headers, which could be manipulated by an attacker. The issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.
CVSS v3.1
Score 5.3medium
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
The vulnerability in Netty's HTTP/2-to-HTTP/1.x translation layer (specifically in Http2StreamFrameToHttpObjectCodec and related components) allows an attacker to include both the :authority pseudo-header and a literal Host header in a single HEADERS frame without proper deduplication or validation. This results in an HttpRequest object with two conflicting Host headers. This flaw exists in Netty versions prior to 4.1.136.Final and 4.2.16.Final and has been addressed in those fixed versions.
Potential Impact
An attacker can manipulate the conflicting Host headers in the HTTP request, potentially causing inconsistent or unexpected behavior in applications relying on Netty's HTTP/2-to-HTTP/1.x translation. The CVSS score of 5.3 (medium severity) indicates limited impact with no confidentiality or availability loss but with potential integrity implications.
Mitigation Recommendations
Upgrade Netty to version 4.1.136.Final or later, or 4.2.16.Final or later, where this vulnerability has been fixed. No other mitigation is indicated by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-c69g-56f8-xwqj
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-59900"]
- Ecosystems
- ["Maven"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6a6150d39c2644c7f8da06de
Added to database: 07/22/2026, 23:22:59 UTC
Last enriched: 10/18/2026, 04:35:08 UTC
Last updated: 10/21/2026, 13:20:22 UTC
Views: 106
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