CVE-2026-67431
- Source
- https://cve.org/CVERecord?id=CVE-2026-67431
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-67431.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-67431
- Aliases
- Published
- 2026-07-29T19:15:32Z
- Modified
- 2026-10-28T02:31:07Z
- Severity
-
- 8.3 (High) CVSS_V4 - 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 CVSS Calculator
- Summary
- MCP Ruby SDK: Ruby SSE Session Poisoning
- Details
-
MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that execute in the victim's session. This issue is fixed in version 0.23.0.
- Database specific
{ "cna_assigner": "GitHub_M", "cwe_ids": [ "CWE-284" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67431.json" }- References
-
- https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67431.json
- 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
Affected packages
Git / github.com/modelcontextprotocol/ruby-sdk
Affected ranges
- Type
- GIT
- Repo
- https://github.com/modelcontextprotocol/ruby-sdk
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixedFixed
- Database specific
-
Show details
{ "extracted_events": [ { "range": [ { "introduced": "0" }, { "fixed": "0.23.0" } ], "source": "AFFECTED_FIELD", "strategy": "StringRangeExpression" }, { "range": [ { "fixed": "35466605319a34e4c7808712ae9bb1ca1afb2356" } ], "source": "REFERENCES_COMMIT" }, { "original_tag": "v0.23.0", "range": [ { "fixed": "95feef2dcfba25d92a8963d14b7a3b279122f36f" } ], "source": "REFERENCES_TAG" } ] }