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TI-2026-85246 Aliases CVE-2026-76892

Malformed JSON requests crash the tsParticles MCP server HTTP process

Priority HIGH 77CWE-248Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-248.

Summary

The tsParticles library and @tsparticles/mcp-server are affected before 4.3.1. In HTTP mode, the POST /mcp handler calls JSON.parse outside a request-level error handler, which is an uncaught exception (CWE-248). An unauthenticated remote attacker who sends one malformed JSON body causes a SyntaxError that terminates the Node.js process, leaving the MCP service unavailable until a supervisor restarts it.

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 calls JSON.parse outside a request-local error boundary in the POST /mcp handler in integrations/mcp-server/src/index.ts. A single unauthenticated malformed JSON body raises a SyntaxError that terminates the Node.js process, leaving the MCP service unavailable until an external supervisor restarts it. This issue is fixed in version 4.3.1.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00291 21st percentileScored 2026-11-07
Fix Fixed tsparticles (tsparticles): 4.3.1mcp-server (@tsparticles): 4.3.1

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

VendorProductAffected versionsFixed inStatusSource
tsparticlestsparticlesbefore 4.3.14.3.1Patch availableCNA
tsparticlesmcp-serverbefore 4.3.14.3.1Patch availableCNA
  • 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

Update tsparticles and @tsparticles/mcp-server to version 4.3.1, which fixes the issue.

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

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-76892
  2. 2026-11-05 CISA SSVC decision points changed
  3. 2026-11-05 Priority changed: MEDIUM → HIGH
  4. 2026-11-06 Affected versions changed · Red Hat
  5. 2026-11-06 CVSS score added · Red Hat

References

Other 3

  • TI-2026-85240 Unbounded request body buffering in tsParticles MCP server CVSS 3.1HIGH 7.5
  • 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

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences