Vulnerability Description
Netty is a network application framework for development of protocol servers and clients. Prior to 4.2.16.Final, Netty's `Http3FrameCodec` buffers incoming data for HTTP/3 reserved frame types up to the wire-specified payload length without limits; `decodeFrame` trusts `payLoadLength`, allowing an attacker to open multiple QUIC streams and send reserved frames with very large payload lengths to cause memory exhaustion and denial of service. This issue is fixed in version 4.2.16.Final.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netty | Netty | >= 4.2.2, < 4.2.16 |
Related Weaknesses (CWE)
References
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bPatch
- https://github.com/netty/netty/releases/tag/netty-4.2.16.FinalRelease Notes
- https://github.com/netty/netty/security/advisories/GHSA-hpcc-26xq-25fvExploitVendor Advisory
FAQ
What is CVE-2026-56816?
CVE-2026-56816 is a vulnerability with a CVSS score of 7.5 (HIGH). Netty is a network application framework for development of protocol servers and clients. Prior to 4.2.16.Final, Netty's `Http3FrameCodec` buffers incoming data for HTTP/3 reserved frame types up to t...
How severe is CVE-2026-56816?
CVE-2026-56816 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-56816?
Check the references section above for vendor advisories and patch information. Affected products include: Netty Netty.