rivemcp@1.18.0
Polymation — the AI animation MCP. Author Rive (.riv/.rev) and Spline; convert Lottie, After Effects, Adobe Animate, Figma and glTF into Rive and back; turn AI art into rigged characters, pixel-art puppets, sprite sheets and flipbooks. Offline, checked in
AI Security Review
scanned 13d ago · by lpm-firewall-aiThe install-time download and later launch of an opaque executable create a real unresolved payload risk. The inspected JavaScript does not show concrete attack behavior, so a warning is appropriate.
Static reason
One or more suspicious static signals were detected.
Trigger
Installing the package runs its postinstall hook; invoking the rivemcp command starts the downloaded executable.
Impact
The executable can act with the invoking user's privileges; its behavior cannot be assessed from this package snapshot.
Mechanism
The hook fetches a platform-specific versioned asset from the rivemcp releases host and writes it into bin/.
AI rationale
The install-time download and later launch of an opaque executable create a real unresolved payload risk. The inspected JavaScript does not show concrete attack behavior, so a warning is appropriate.
Evidence
package.jsonscripts/postinstall.mjsbin/rivemcp.mjsbin/rivemcp
Network endpoints1
github.com/paradoxsyn/rivemcp-releases/releases/download/v${VERSION}/${asset.name}
Decision evidence
public snapshotAI called this Suspicious at 85.0% confidence as Dangerous Capability with medium false-positive risk.
Evidence for warning
- The manifest runs scripts/postinstall.mjs during installation; the hook downloads a platform executable from the rivemcp releases host and writes it into bin/.
- The CLI shim starts that downloaded executable when the command is invoked; its behavior is absent from this package snapshot.
- The flagged Rive dependency files are package entrypoints for canvas and WebGL2 runtimes; the inspected excerpts implement path and string processing, not a demonstrated attack.
Evidence against
- The installer selects a versioned release asset and the inspected source does not execute it during installation.
- No concrete credential theft, destructive behavior, or other attack was established in the inspected JavaScript.
Behavioral surface
ChildProcessFilesystemNetwork
UrlStrings
NoLicense
Source & flagged code
7 flaggedpackage.jsonView file
•scripts.postinstall = node scripts/postinstall.mjs
High
Install Time Lifecycle Scripts
Package defines install-time lifecycle scripts.
package.jsonView on unpkg•scripts.postinstall = node scripts/postinstall.mjs
Medium
Ambiguous Install Lifecycle Script
Install-time lifecycle script is not statically allowlisted and needs review.
package.jsonView on unpkg.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/1/npm-linux/canvas_advanced.mjsView file
45Za(a.split("/").filter(d=>!!d),!b).join("/"))||b||(a=".");a&&c&&(a+="/");return(b?"/":"")+a},ab=a=>{var b=/^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/.exec(a).sl
Medium
Findings
1 High7 Medium4 Low
HighInstall Time Lifecycle Scriptspackage.json
MediumAmbiguous Install Lifecycle Scriptpackage.json
MediumNetwork
MediumSuspicious Dependency Evidence.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/1/npm-linux/canvas_advanced.mjs
MediumSuspicious Dependency Evidence.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/1/npm-linux/canvas_advanced.mjs
MediumSuspicious Dependency Evidence.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/1/npm-linux/canvas_advanced.mjs
MediumSuspicious Dependency Evidence.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/1/npm-linux/canvas_advanced.mjs
MediumSuspicious Dependency Evidence.lpm-dependency-evidence-3433ffe4-0d14-4699-84bb-4c7bcc43e025/2/npm-linux/webgl2_advanced.mjs
LowScripts Present
Affected versions and remediation
This report applies to rivemcp@1.18.0.
See all versions of rivemcp for other recorded verdicts.
- Review the evidence and your use of rivemcp@1.18.0 before allowing it. Restrict the permissions described in this report.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
Evidence last updated: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.