CVE-2026-67431

RubyGems/mcp CVE-2026-67431: high, EPSS 0.48%

MCP Ruby SDK: Ruby SSE Session Poisoning

Action: Upgrade mcp to 0.23.0 or later.

bundle update mcp

Affected

Fixed versions

Sources

• osv: GHSA-5p9g-j988-pcwv
• https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-5p9g-j988-pcwv
• https://nvd.nist.gov/vuln/detail/CVE-2026-67431
• https://github.com/modelcontextprotocol/ruby-sdk/commit/35466605319a34e4c7808712ae9bb1ca1afb2356
• https://github.com/modelcontextprotocol/ruby-sdk
• https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0

CVE-2026-67431 · published 2026-07-30T14:44:28Z · modified 2026-07-30T15:00:31.159150886Z · JSON