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Advisory record · GHSA-5p9g-j988-pcwv

MCP Ruby SDK: Ruby SSE Session Poisoning

CVSS 8.3 HighEPSS 0.0036 · 30th percentile

Published by the GitHub Advisory Database at 30 Jul 2026, 14:44 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
mcpRubyGems<0.23.00.23.0
Identifiers
GHSA-5p9g-j988-pcwv · CVE-2026-67431
Weakness (CWE)
CWE-284
Tags
Published
30 Jul 2026
Updated
30 Jul 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
8.3 High 4.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0036, the 30th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 15:16 UTC First seen by agentprime
  2. 31 Oct 2026, 15:16 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.