GHSA-22jm-h49p-29qw - MCP TypeScript SDK: Experimental tasks were not tied to the session that created them
### Summary
In affected versions, the experimental tasks feature (`taskStore`) did not check which session created a task. Clients sharing one `InMemoryTaskStore` could list, read and cancel each other's tasks.
Experimental tasks are deprecated. The 2026-07-28 specification replaced them with a redesigned extension. The best course of action is to stop using them.
### Am I affected?
Only if your HTTP server passes `taskStore` to `McpServer` or `Server`. If `grep -ri taskstore --exclude-dir=node_modules .` finds nothing, you are not affected.
Affected versions: `@modelcontextprotocol/sdk` 1.24.0 through 1.31.0. The 2.x packages are not affected.
### Fix
Upgrade to `@modelcontextprotocol/sdk` 1.32.0 or later. Each task is now tied to the session that created it, so a client that starts a new session can no longer reach its earlier tasks.
If you cannot upgrade yet, remove `taskStore`, or create one `InMemoryTaskStore` per session.
HIGH
Severity & confidence
Source severityhigh
Platform severityhigh
Confidencemedium
Exploitationunknown
CVSS8.6
Affected
Vendors@modelcontextprotocol
Products@modelcontextprotocol/sdk
Reporting sources (1)
GitHub Security Advisories
Timeline & provenance
Published2026-10-20T18:26:54
Last updated2026-10-21T06:41:43
Ingested2026-10-20T18:37:50
FreshnessNEAR-REAL-TIME
Threat typeadvisory
Recommended action
Review the advisory and upgrade affected packages to the first patched version.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a single or secondary source; treat as indicative, verify before acting.
Source type: vendor ยท Original: GitHub Security Advisories