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Advisory record · GHSA-hpcc-26xq-25fv

Netty: Memory Exhaustion via HTTP/3 Reserved Frame Types

CVSS 7.5 HighEPSS 0.0064 · 51st percentile

Published by the GitHub Advisory Database at 22 Jul 2026, 21:42 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
io.netty:netty-codec-http3Maven<4.2.16.Final4.2.16.Final
Identifiers
GHSA-hpcc-26xq-25fv · CVE-2026-56816
Weakness (CWE)
CWE-400
Tags
Published
22 Jul 2026
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Netty's io.netty:netty-codec-http3 package, versions before 4.2.16.Final, buffers data for HTTP/3 reserved frame types without limits, trusting the payload length sent on the wire. A remote attacker who can open HTTP/3 streams can send reserved frames declaring very large payloads, causing memory exhaustion and denial of service. Upgrade to io.netty:netty-codec-http3 version 4.2.16.Final or later.

Written 2 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
7.5 High 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0064, the 51st percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:16 UTC First seen by agentprime
  2. 31 Oct 2026, 14:16 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.