tsParticles: Unbounded HTTP Request Body Buffering in @tsparticles/mcp-server Leads to Remote DoS
Affects tsparticles and @tsparticles/mcp-server before 4.3.1 when the MCP server runs in HTTP mode, which the official Docker image enables by default. CVSS scores it High (7.5). Fixed in 4.3.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 4.3.1
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
CVE-2026-63655 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.5 (high) and affects tsparticles and mcp-server; fixed in 4.3.1.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 30/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Default setups
- Fix
- Fixed in 4.3.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The @tsparticles/mcp-server package, in its HTTP mode, can be remotely crashed by an unauthenticated attacker who sends a very large request body to the POST /mcp endpoint, exhausting the Node.js process's memory and terminating the service, including under the official Docker configuration. The attack is carried out over the network without logging in, and it affects availability only, not confidentiality or integrity.
Read the original description
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.
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 4.3.1.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- tsparticles tsparticles
fixed in 4.3.1
- @tsparticles mcp-server
fixed in 4.3.1
Evidence 5
- Advisory
- Repository
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-63655
Is CVE-2026-63655 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
The HTTP server mode of @tsparticles/mcp-server keeps accumulating every incoming chunk of a request body without limit. A large streamed request body can exhaust Node.js process memory, crashing the service with an out-of-memory kill.Source: github.com
Which versions are affected by CVE-2026-63655?
tsparticles: before 4.3.1. mcp-server: before 4.3.1.Source: cve.now feed data
Am I affected, and how do I check?
Versions of tsparticles and @tsparticles/mcp-server before 4.3.1 that run HTTP server mode, which serves POST /mcp. The official Docker image starts HTTP mode by default, so check the installed @tsparticles/mcp-server version and whether HTTP mode is enabled.Source: github.com
How do I fix CVE-2026-63655?
Upgrade tsparticles and @tsparticles/mcp-server to 4.3.1 or later, the fixed version listed for both packages.Source: github.com