Prior to versions 4.1.135.Final and 4.2.15.Final, Netty HTTP/2 max header size handling produces an attack similar to HTTP/2 Rapid Reset. (CVE-2026-50560)
Description
Netty versions prior to 4.1.135.Final and 4.2.15.Final have a vulnerability in HTTP/2 max header size handling that can cause an attack similar to HTTP/2 Rapid Reset. When a client sends the SETTINGS_MAX_HEADER_LIST_SIZE setting, Netty processes the request but throws an exception while writing response headers. This behavior can disrupt service availability. The issue is patched in versions 4.1.135.Final and 4.2.15.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=questingpkg: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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Netty, a network application framework, has a vulnerability in its HTTP/2 max header size handling prior to versions 4.1.135.Final and 4.2.15.Final. Specifically, when a client sends the SETTINGS_MAX_HEADER_LIST_SIZE setting, Netty reads and proxies the request, attempts to produce a response, but then throws an exception during response header writing. This results in behavior similar to the HTTP/2 Rapid Reset attack but with a different network signature. The vulnerability can lead to denial of service conditions. The issue is fixed in versions 4.1.135.Final and 4.2.15.Final.
Potential Impact
The vulnerability can cause Netty servers to throw exceptions during response header writing when processing HTTP/2 requests with certain max header size settings. This can disrupt normal service operation, leading to denial of service (availability impact). There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Upgrade Netty to version 4.1.135.Final or later, or 4.2.15.Final or later, where this vulnerability is patched. No other mitigation is specified or required.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-50560
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:25.10","Ubuntu:26.10","Ubuntu:Pro:26.04:LTS"]
- Cvss Version
- 3.1
Threat ID: 6ad3f60e2cdf04f656664117
Added to database: 10/17/2026, 22:26:22 UTC
Last enriched: 10/18/2026, 00:58:48 UTC
Last updated: 10/18/2026, 00:58:48 UTC
Views: 2
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