Unbounded request body buffering in tsParticles MCP server
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
The tsparticles package and @tsparticles/mcp-server are affected before 4.3.1. The HTTP mode of the MCP server accumulates every request body chunk in memory without a cumulative size limit (CWE-400). An unauthenticated remote attacker can send an arbitrarily large POST /mcp body to exhaust Node.js process memory and terminate the service. Confidentiality and integrity are not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
tsParticles is a TypeScript library for creating highly customizable particle animations. Prior to 4.3.1, the HTTP mode of @tsparticles/mcp-server accepts unauthenticated POST /mcp requests in integrations/mcp-server/src/index.ts and accumulates every request-body chunk in a Buffer[] without a cumulative size limit before Buffer.concat and JSON.parse. A remote attacker can stream an arbitrarily large body to exhaust Node.js process memory and terminate the service, including in the official Docker configuration that exposes HTTP mode on 0.0.0.0:3000. Confidentiality and integrity are not affected. This issue is fixed in version 4.3.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| tsparticles | tsparticles | before 4.3.1 | 4.3.1 | Patch available | CNA |
| tsparticles | mcp-server | before 4.3.1 | 4.3.1 | Patch available | CNA |
- tsparticles Vendortsparticles Affected before 4.3.1 Fixed in 4.3.1 Patch available CNA
- mcp-server Vendortsparticles Affected before 4.3.1 Fixed in 4.3.1 Patch available CNA
Remediation
Upgrade tsparticles and @tsparticles/mcp-server to version 4.3.1.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA tsparticles (tsparticles) Fixed in 4.3.1
- Fix · CNA mcp-server (@tsparticles) Fixed in 4.3.1
Vendor assessments
Timeline
- 2026-11-04 Threatist record created from CVE-2026-63655
- 2026-11-05 CISA SSVC decision points changed
- 2026-11-05 Priority changed: MEDIUM → HIGH
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
Other 5
- https://github.com/tsparticles/tsparticles/security/advisories/GHSA-447x-qqwf-m7xq
- https://github.com/tsparticles/tsparticles/pull/5875
- https://github.com/tsparticles/tsparticles/commit/25fb70e7f527a91568adaef576570289083f243b
- https://github.com/tsparticles/tsparticles/commit/7b3a9488d4201fe9ddd5fec05f4a2ae65d3627ea
- https://github.com/tsparticles/tsparticles/releases/tag/v4.3.1
More tsparticles vulnerabilities
- TI-2026-85246 Malformed JSON requests crash the tsParticles MCP server HTTP process CVSS 4.0HIGH 8.7
- TI-2026-85241 tsParticles MCP server lets one anonymous session block new clients CVSS 4.0MEDIUM 6.9
- TI-2026-85245 Command injection in tsParticles stable publish workflow via release notes CVSS 4.0HIGH 7.5
Sources
- CVE-2026-63655 · CVE Program
- CVE-2026-63655 · NVD
- FIRST EPSS
- CVE-2026-63655 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences