CVE-2026-55831

Name of the Vulnerable Software and Affected Versions Netty versions prior to 4.1.136.Final Netty versions prior to 4.2.16.Final

Description The SPDY SETTINGS decoder accepts a peer-declared SETTINGS entry count up to the 24-bit frame-length limit and materializes every unique setting ID in DefaultSpdySettingsFrame. This allows a remote SPDY/3.1 peer to send a syntactically valid SETTINGS frame of approximately 2 MiB, resulting in the creation of 262,144 map entries. This process amplifies network input into heap growth and ordered-map insertion work, leading to a denial of service.

Recommendations Update to version 4.1.136.Final. Update to version 4.2.16.Final.