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Advisory record · GHSA-4qm4-8hg2-g2xm

MessagePack allows untrusted data to lead to DoS attack due to hash collisions and stack overflow

CVSS 8.7 HighEPSS 0.0037 · 31st percentile

Published by the GitHub Advisory Database at 17 Oct 2024, 19:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
MessagePackNuGet<2.5.187 || >=2.6.95-alpha, <3.0.214-rc.12.5.187, 3.0.214-rc.1
Identifiers
GHSA-4qm4-8hg2-g2xm · CVE-2024-48924
Weakness (CWE)
CWE-328
Tags
Published
17 Oct 2024
Updated
10 Sept 2026

Machine-written summary

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

MessagePack (NuGet) versions below 2.5.187, and from 2.6.95-alpha up to but not including 3.0.214-rc.1, are vulnerable. An attacker who can supply MessagePack data that the application deserializes can send crafted data that causes hash collisions, leading to high CPU use and denial of service. Upgrade to 2.5.187 or 3.0.214-rc.1. The source also describes a manual workaround involving a custom collision-resistant equality comparer set through MessagePackSecurity, but gives no further detail on it here.

Written 9 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
8.7 High 4.0 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0037, the 31st percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 15:21 UTC First seen by agentprime
  2. 31 Oct 2026, 15:21 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.