tsParticles: Unbounded HTTP Request Body Buffering in @tsparticles/mcp-server Leads to Remote DoS

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-63655: 0.43% estimated exploitation activity in the next 30 days; percentile 37.67 (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 server mode of `@tsparticles/mcp-server` accumulates all incoming request body chunks into an in-memory `Buffer[]` array with no size limit before calling `JSON.parse`. An unauthenticated remote attacker can stream an arbitrarily large body to `POST /mcp`, exhausting the Node.js process memory and causing a Denial of Service. The official Docker image ships with HTTP mode enabled by default (`--port 3000` on `0.0.0.0`), making this exploitable without any special configuration in containerized deployments.

Details The vulnerability exists in `integrations/mcp-server/src/index.ts` at lines 399–407. The `POST /mcp` request handler resolves a `Promise` that pushes every incoming data chunk into a `Buffer[]` array without checking the cumulative size, a `Content-Length` header, or any other guard: ```ts // integrations/mcp-server/src/index.ts:399-407 if (req.method === "POST" && req.url === "/mcp") { const body = await new Promise ((resolve, reject) => { const…

Published by the source

9 Nov 2026, 21:10 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-447x-qqwf-m7xq

2. Revision 1 · created · 9 Nov 2026

   Published from ghsa record GHSA-447x-qqwf-m7xq

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# Patch Next advisory brief: CVE-2026-63655

Advisory: tsParticles: Unbounded HTTP Request Body Buffering in @tsparticles/mcp-server Leads to Remote DoS
IDs: CVE-2026-63655, GHSA-447x-qqwf-m7xq
Record: https://patchnext.com/advisories/cve-2026-63655 (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 7.5)
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-447x-qqwf-m7xq (GitHub-reviewed advisory GHSA-447x-qqwf-m7xq lists affected ranges: npm @tsparticles/mcp-server >=0 <4.3.1)
- Verified: https://osv.dev/vulnerability/GHSA-447x-qqwf-m7xq (OSV record GHSA-447x-qqwf-m7xq lists affected ranges: npm @tsparticles/mcp-server >=0 <4.3.1 (fixed))

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