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CVE-2026-55831GHSA-6JQX-86GH-F27W

Netty SPDY SETTINGS frame count materializes unbounded settings map

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 4.2.16.Final, 4.1.136.Final
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

Netty is a network application framework for development of protocol servers and clients. Prior to 4.1.136.Final and 4.2.16.Final, Netty's 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`, allowing a remote SPDY/3.1 peer to send a syntactically valid roughly 2 MiB SETTINGS frame that creates 262144 map entries and amplifies network input into heap growth and ordered-map insertion work. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • netty netty

    From 4.2.0.Final · fixed in 4.2.16.Final; From 4.1.0.Final · fixed in 4.1.136.Final

  • io.netty:netty-codec-httpMaven

    From 4.2.0.Final · fixed in 4.2.16.Final

  • io.netty:netty-codec-httpMaven

    From 4.1.0.Final · fixed in 4.1.136.Final

References 5

GitHub · netty/netty