AIKIDO-2026-275094
netty-codec-http2 is vulnerable to Denial of Service (DoS)
53
Medium Risk
This Affects:
netty-codec-http2TL;DR
A remote client can send an HTTP/2 SETTINGS frame advertising an extremely large header-table size, which DefaultHttp2HeadersEncoder accepts without a cap. The HpackEncoder then retains every unique outbound header indefinitely, degrading header lookups to O(n^2). Throughput collapses as the server generates more unique headers, causing a denial of service. The fix constrains the accepted header-table size.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range.
Background info
netty-codec-http2 is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 4.1.137.Final and 4.2.0.Final - 4.2.17.Final.
How to fix this
Upgrade the io.netty:netty-codec-http2 library to the patch version.
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SOC 2Compliant
ISO 27001CompliantISO 42001Compliant
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