MCP TypeScript SDK: Experimental tasks were not tied to the session that created themGHSA-22jm-h49p-29qw
HIGHFix: modelcontextprotocol/typescript-sdk#2925GHSA-22jm-h49p-29qw is a high-severity (CVSS 8.6) CWE-639 vulnerability in @modelcontextprotocol/sdk. A fix is available for @modelcontextprotocol/sdk — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-22jm-h49p-29qw by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@modelcontextprotocol/sdknpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @modelcontextprotocol/sdk | ≥ 1.24.0&&< 1.32.0 | 1.32.0npm install @modelcontextprotocol/sdk@1.32.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @modelcontextprotocol/sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @modelcontextprotocol/sdk to 1.32.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-22jm-h49p-29qw is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat Product Security has rated this flaw as having an Important severity because missing session boundaries within the shared task storage mechanism allow concurrent connections to inspect, enumerate, or abort tasks belonging to other clients. This classification reflects the high risk of cross-session data…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for GHSA-22jm-h49p-29qw (CC BY 4.0)
Frequently Asked Questions
Is GHSA-22jm-h49p-29qw in your dependencies?
Find it across npm, including transitive dependencies.