CVE-2026-25536: lfprojects mcp_typescript_sdk Race Condition
Vulnerability summary
CVE-2026-25536 is a high (CVSS 7.1) Race Condition vulnerability in lfprojects mcp_typescript_sdk. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 04-02-2026PublishedVulnerability first disclosed.
- 15-07-2026Last modifiedVulnerability information updated.
Description
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 metrics
5 scores · 5 sources · 1 version- OSV · WolfiEcosystem advisory · calculated7.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- OSV · NpmEcosystem advisory · calculated7.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- OSV · ChainguardEcosystem advisory · calculated7.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
- NVDNIST7.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
31%
Versus all other CVEs
30-day change
+0.11 pp
From 0.28% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
- CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Affected systems
Chainguard12 products
- gemini-cli< 0.49.0-r4
- kibana-9.1< 9.1.10-r4
- kibana-9.1-iamguarded< 9.1.10-r4
- kibana-9.2< 9.2.5-r0
- kibana-9.2-iamguarded< 9.2.5-r0
Wolfi2 products
- langfuse-3< 3.153.0-r0
- langfuse-3-worker< 3.153.0-r0
@modelcontextprotocol1 product
- sdk≥ 1.10.0, < 1.26.0
Lfprojects1 product
- mcp_typescript_sdk≥ 1.10.0, < 1.26.0
Modelcontextprotocol1 product
- typescript-sdk≥ 1.10.0, < 1.26.0
5 vendors · 17 products
References
10 links- github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7X Refsource CONFIRMAdvisoryWEBMitigationVendor Advisory
- github.com/modelcontextprotocol/typescript-sdk/issues/204X Refsource MISCREPORTWEBIssue TrackingVendor Advisory
- github.com/modelcontextprotocol/typescript-sdk/issues/243X Refsource MISCREPORTWEBIssue TrackingVendor Advisory
