CVE-2026-25536
@modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
CVSS Score
7.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-362 |
| Vendor | modelcontextprotocol |
| Product | typescript-sdk |
| Published | Feb 4, 2026 |
| Last Updated | Jun 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None
Affected Versions
modelcontextprotocol / typescript-sdk
>= 1.10.0, < 1.26.0
References
github.com: https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7 github.com: https://github.com/modelcontextprotocol/typescript-sdk/issues/204 github.com: https://github.com/modelcontextprotocol/typescript-sdk/issues/243 access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-25536 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2436937 security.access.redhat.com: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json access.redhat.com: https://access.redhat.com/errata/RHSA-2026:3960