Netty susceptible to HTTP/2 Reset Attack with different on-the-wire signature
CVE-2026-50560
What is CVE-2026-50560?
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 Version(s)
netty >= 4.2.0.Final, < 4.2.15.Final < 4.2.0.Final, 4.2.15.Final
netty < 4.1.135.Final < 4.1.135.Final