CVE-2026-50560: Netty

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Netty is a network application framework for development of protocol servers and clients. 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. There is a setting in the http2 specification called `SETTINGS_MAX_HEADER_LIST_SIZE`. When a client sends that setting to Netty, it appears that Netty will behave as follows: read the request; proxy the request to the origin; attempt to produce a response; and create an exception while writing the headers for the response. Functionally, this should be similar to the http2 reset attack, but with a different on-the-wire signature. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Affected products

• Netty Netty: before 4.1.135 (fixed in 4.1.135); from 4.2.0, before 4.2.15 (fixed in 4.2.15)

Published 2026-06-12. Last modified 2026-06-17.