tsParticles: Malformed JSON requests can terminate the @tsparticles/mcp-server HTTP process

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-76892: 0.29% estimated exploitation activity in the next 30 days; percentile 21.92 (FIRST EPSS, 2026-11-10). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The HTTP mode of `@tsparticles/mcp-server` parses incoming `/mcp` request bodies with `JSON.parse()` outside a request-local error boundary. A single malformed JSON request causes the async request handler to throw and terminates the Node.js process. This was verified on `v4.3.0` at commit `0266d469aa2d719cb66a9c6bf09aded4186ec17c`. Version `4.3.1` appears to fix this by returning HTTP 400 for invalid JSON.

Affected Code The vulnerable handler is: if (req.method === "POST" && req.url === "/mcp") { const body = await new Promise ((resolve, reject) => { const chunks: Buffer[] = []; req.on("data", (chunk) => chunks.push(Buffer.from(chunk))); req.on("end", () => resolve(Buffer.concat(chunks).toString("utf8"))); req.on("error", reject); }); const parsedBody = body ? JSON.parse(body) : undefined; await transport.handleRequest(req, res, parsedBody); } The `JSON.parse()` call is not wrapped in `try/catch`.

Reproduction Start the HTTP server and send this malformed request:…

Published by the source

9 Nov 2026, 21:13 UTC

Last modified by the source

9 Nov 2026, 21:30 UTC

Source last checked

10 Nov 2026, 06:25 UTC

1. Revision 2 · amended · 10 Nov 2026

   Amended from osv record GHSA-4p8p-pjpq-2w7h

2. Revision 1 · created · 9 Nov 2026

   Published from ghsa record GHSA-4p8p-pjpq-2w7h

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# Patch Next advisory brief: CVE-2026-76892

Advisory: tsParticles: Malformed JSON requests can terminate the @tsparticles/mcp-server HTTP process
IDs: CVE-2026-76892, GHSA-4p8p-pjpq-2w7h
Record: https://patchnext.com/advisories/cve-2026-76892 (revision 2, source checked 10 Nov 2026, 06:25 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @tsparticles/mcp-server 4.3.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @tsparticles/mcp-server: affected < 4.3.1; fixed in 4.3.1

## Suggested inspection (read-only)
- `npm ls @tsparticles/mcp-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @tsparticles/mcp-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4p8p-pjpq-2w7h (GitHub-reviewed advisory GHSA-4p8p-pjpq-2w7h lists affected ranges: npm @tsparticles/mcp-server >=0 <=4.3.0)
- Verified: https://osv.dev/vulnerability/GHSA-4p8p-pjpq-2w7h (OSV record GHSA-4p8p-pjpq-2w7h lists affected ranges: npm @tsparticles/mcp-server >=0 <4.3.1 (fixed))

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