High 7.1Published Feb 4, 2026

CVE-2026-25536@modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse

Updated under an hour ago (Oct 27, 2026, 11:50 AM ET)

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It affects modelcontextprotocol typescript-sdk and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for modelcontextprotocol typescript-sdk

Exploited in the last 30 days

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.

CVSS: 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Weakness (CWE): CWE-362, CWE-367
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Modified
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

modelcontextprotocol typescript-sdk modelcontextprotocol:typescript_sdk (from the name)	from 1.10.0, < 1.26.0	CNA record
Red Hat Red Hat Ansible Automation Platform 2.6 redhat:ansible_automation_platform	from 1772196222 not affected	CISA ADP
lfprojects mcp_typescript_sdk lfprojects:mcp_typescript_sdk	from 1.10.0 before 1.26.0	NVD

References

References

https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7	x-refsource-confirm, mitigation, vendor-advisory
https://github.com/modelcontextprotocol/typescript-sdk/issues/204	x-refsource-misc, issue-tracking, vendor-advisory
https://github.com/modelcontextprotocol/typescript-sdk/issues/243	x-refsource-misc, issue-tracking, vendor-advisory
https://access.redhat.com/errata/RHSA-2026:3960
https://access.redhat.com/security/cve/CVE-2026-25536
https://bugzilla.redhat.com/show_bug.cgi?id=2436937
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.