@mastra/deployer-sandbox@0.3.26
Deploy a Mastra server into any workspace sandbox that supports networking and get a live public URL
AI Security Review
scanned 22h ago · by lpm-firewall-aiThe package’s deployer behavior matches its stated purpose, and the flagged credential paths do not show credentials sent to an unrelated host. The bundled Studio does automatically enable PostHog autocapture without a clear disclosure in the reviewed source, so this is suspicious runtime telemetry rather than a demonstrated exfiltration attack.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
The Studio UI loads in a browser, unless telemetry is disabled or browser constraints block it.
Impact
Studio usage and interaction data may be sent to an analytics provider. The reviewed source does not establish credential or application-record exfiltration.
Mechanism
Studio initializes PostHog at https://us.posthog.com; the bundled SDK enables autocapture by default.
AI rationale
The package’s deployer behavior matches its stated purpose, and the flagged credential paths do not show credentials sent to an unrelated host. The bundled Studio does automatically enable PostHog autocapture without a clear disclosure in the reviewed source, so this is suspicious runtime telemetry rather than a demonstrated exfiltration attack.
Evidence
dist/studio/assets/main-C4wZvSZw.js
Network endpoints1
us.posthog.com
Decision evidence
public snapshotAI called this Suspicious at 87.0% confidence as Unknown with medium false-positive risk.
Evidence for warning
- The bundled Studio initializes PostHog at https://us.posthog.com when it loads, unless browser constraints or MASTRA_TELEMETRY_DISABLED prevent it.
- The bundled PostHog SDK config has autocapture enabled by default.
- The Studio provides MASTRA_TELEMETRY_DISABLED as an opt-out, but the reviewed source does not disclose what telemetry is collected when enabled.
Evidence against
- The manifest describes a sandbox deployer and exports its runtime entry points from dist/.
- The deployer sends an optional Vercel token to api.vercel.com for the explicitly configured Edge Config alias update.
- Deployment environment variables are sent to the selected remote sandbox, with a warning that sandbox users can read them.
- The review found no evidence that credentials or rich application records are sent to PostHog.
Behavioral surface
ChildProcessEnvironmentVarsFilesystemNetworkWebSocket
HighEntropyStrings
Source & flagged code
5 flaggeddist/studio/assets/main-C4wZvSZw.jsView file
•Credential-bearing message sent to a fixed external iframe in dist/studio/assets/main-C4wZvSZw.js:
import{a as e,i as t,n,r,t as i}from"./rolldown-runtime-BWaJ3C7D.js";import{t as a}from"./preload-helper-CRzLMJPS.js";import{$t as o,At as s,B as c,Bt as l,C as u,Ct as d,Dt as f,E...
`+e.stack}}var ke=Object.prototype.hasOwnProperty,Ae=t.unstable_scheduleCallback,je=t.unstable_cancelCallback,Me=t.unstable_shouldYield,Ne=t.unstable_requestPaint,Pe=t.unstable_now...
]))`;continue}}n.s&&r[e]===`.`?i+=o?`${r[e]}\r\n`:`[${r[e]}\r\n]`:(i+=r[e],r[e]===`\\`?a=!0:o&&r[e]===`]`?o=!1:!o&&r[e]===`[`&&(o=!0))}try{new RegExp(i)}catch{return console.warn(`...
Set the \`cycles\` parameter to \`"ref"\` to resolve cyclical schemas with defs.`)}for(let n of e.seen.entries()){let r=n[1];if(t===n[0])a(n);else{if
Critical
Hardcoded Runtime Data Exfiltration
Source sends credentials or rich application records to a package-controlled external receiver enabled by default.
dist/studio/assets/main-C4wZvSZw.jsView on unpkg•path = dist/studio/assets/main-C4wZvSZw.js
kind = oversized_source_file
sizeBytes = 6587272
magicHex = [redacted]
Medium
Oversized Source File
Package contains source files above the normal full-analysis size ceiling.
dist/studio/assets/main-C4wZvSZw.jsView on unpkgFindings
1 Critical1 High6 Medium4 Low
CriticalHardcoded Runtime Data Exfiltrationdist/studio/assets/main-C4wZvSZw.js
HighSemantic Analysis Limiteddist/index.cjs#virtual:normalized:round1
MediumNetwork
MediumEnvironment Vars
MediumOversized Source Filedist/studio/assets/main-C4wZvSZw.js
MediumStructural Risk Force Deep Review
MediumAi Review Evidencedist/studio/assets/main-C4wZvSZw.js
MediumAi Review Evidencedist/studio/assets/main-C4wZvSZw.js
LowScripts Present
LowFilesystem
LowHigh Entropy Strings
LowUrl Strings
Affected versions and remediation
This report applies to @mastra/deployer-sandbox@0.3.26.
See all versions of @mastra/deployer-sandbox for other recorded verdicts.
- Review the evidence and your use of @mastra/deployer-sandbox@0.3.26 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.