{"id":"CVE-2026-25536","title":"MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients","summary":"MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multi…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-362","CWE-367"],"vendor":"lfprojects","product":"mcp_typescript_sdk","affected":["mcp_typescript_sdk >= 1.10.0, < 1.26.0"],"patched":["mcp_typescript_sdk 1.26.0"],"published":"2026-02-04","updated":"2026-06-30","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-25536","references":[{"url":"https://github.com/modelcontextprotocol/typescript-sdk/issues/204","label":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/typescript-sdk/issues/243","label":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7","label":"security-advisories@github.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:3960","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-25536","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2436937","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json","label":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"tags":["nvd"],"epss":0.00277,"epssPercentile":0.20426,"ingestedAt":"2026-07-03T18:53:52.170Z","slug":"CVE-2026-25536","body":"## Overview\n\nMCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. This issue has been patched in version 1.26.0.\n\n## Affected\n\n- `mcp_typescript_sdk >= 1.10.0, < 1.26.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `mcp_typescript_sdk 1.26.0`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}