{"id":"CVE-2026-25536","aliases":["GHSA-345p-7cg4-v4c7"],"url":"https://o3.security/vulnerability/CVE-2026-25536","summary":"@modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse","details":"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 multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. This issue has been patched in version 1.26.0.","published":"2026-02-04T21:29:38.276Z","modified":"2026-07-16T03:31:17.855024175Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@modelcontextprotocol/sdk","fixedVersion":"1.26.0"}],"fix":null,"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:3960"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-25536"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25536.json"},{"type":"ADVISORY","url":"https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25536"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2436937"},{"type":"REPORT","url":"https://github.com/modelcontextprotocol/typescript-sdk/issues/204"},{"type":"REPORT","url":"https://github.com/modelcontextprotocol/typescript-sdk/issues/243"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-16T03:31:17.855024175Z"}}