resend-cli@2.27.0
The official CLI for Resend
AI Security Review
scanned 1d ago · by lpm-firewall-aiThe CLI sends usage telemetry by default, but displays its notice only in interactive sessions, leaving noninteractive use undisclosed. The collected fields are limited to usage metadata, so this warrants a telemetry warning rather than a malicious verdict.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
A normal CLI command runs, except `update` and `telemetry`.
Impact
The vendor receives command usage metadata without a notice in noninteractive sessions; the source does not show credential or file-content collection.
Mechanism
The CLI creates a telemetry payload containing usage metadata and a random identifier, then starts a background flush to PostHog. The notice is gated on interactive use.
AI rationale
The CLI sends usage telemetry by default, but displays its notice only in interactive sessions, leaving noninteractive use undisclosed. The collected fields are limited to usage metadata, so this warrants a telemetry warning rather than a malicious verdict.
Evidence
dist/cli.cjstelemetry-idtelemetry-spool/resend-telemetry-<random UUID>.jsontelemetry-notice-shown
Network endpoints1
us.i.posthog.com/capture/
Decision evidence
public snapshotAI called this Suspicious at 90.0% confidence as Dangerous Capability with medium false-positive risk.
Evidence for warning
- Every normal CLI invocation except `update` and `telemetry` triggers usage tracking by default.
- Tracking sends command name, version, OS, Node version, interaction mode, install method, and optional flag names to PostHog; noninteractive runs suppress the notice.
- The notice and opt-out are shown only when the CLI is interactive, while telemetry is disabled only by `DO_NOT_TRACK=1` or `RESEND_TELEMETRY_DISABLED=1`. The noninteractive default is undisclosed runtime telemetry.
Evidence against
- The payload contains usage metadata and a random identifier, not credentials, command output, or file contents.
- Interactive users receive a notice and an opt-out instruction.
- The manifest has no install, preinstall, or postinstall lifecycle hook; the download-and-run text is an upgrade instruction.
Behavioral surface
ChildProcessCryptoDynamicRequireEnvironmentVarsFilesystemNetwork
Source & flagged code
10 flaggeddist/cli.cjsView file
1Source sends the broad process environment to a literal external destination.
L1: #!/usr/bin/env node
L2: "use strict";var op=Object.create;var zi=Object.defineProperty;var ip=Object.getOwnPropertyDescriptor;var rp=Object.getOwnPropertyNames;var np=Object.getPrototypeOf,ap=Object.proto...
L3: `)}displayWidth(t){return wn(t).length}styleTitle(t){return t}styleUsage(t){return t.split(" ").map(o=>o==="[options]"?this.styleOptionText(o):o==="[command]"?this.styleSubcommandT...
...
L13: (Did you mean one of ${i.join(", ")}?)`:i.length===1?`
L14: (Did you mean ${i[0]}?)`:""}Un.suggestSimilar=fp});var Rn=Pe(ur=>{var hp=require("node:events").EventEmitter,lr=require("node:child_process"),dt=require("node:path"),Mo=require("no...
L15: - specify the name in Command constructor or using .name()`);ret
Critical
Hardcoded Runtime Data Exfiltration
Source sends credentials or rich application records to a package-controlled external receiver enabled by default.
dist/cli.cjsView on unpkg · L113(Did you mean one of ${i.join(", ")}?)`:i.length===1?`
L14: (Did you mean ${i[0]}?)`:""}Un.suggestSimilar=fp});var Rn=Pe(ur=>{var hp=require("node:events").EventEmitter,lr=require("node:child_process"),dt=require("node:path"),Mo=require("no...
L15: - specify the name in Command constructor or using .name()`);return o=o||{},o.isDefault&&(this._defaultCommandName=t._name),(o.noHelp||o.hidden)&&(t._hidden=!0),this._registerComma...
...
L26: Expecting one of '${i.join("', '")}'`);let r=`${t}Help`;return this.on(r,n=>{let a;typeof o=="function"?a=o({error:n.error,command:n.command}):a=o,a&&n.write(`${a}
L27: `)}),this}_outputHelpIfRequested(t){let o=this._getHelpOption();o&&t.find(r=>o.is(r))&&(this.outputHelp(),this._exit(0,"commander.helpDisplayed","(outputHelp)"))}};function Fn(e){r...
Findings
3 Critical5 High5 Medium5 Low
CriticalHardcoded Runtime Data Exfiltrationdist/cli.cjs
CriticalCommand Output Exfiltrationdist/cli.cjs
CriticalTrigger Reachable Dangerous Capabilitydist/cli.cjs
HighChild Processdist/cli.cjs
HighSame File Env Network Executiondist/cli.cjs
HighSandbox Evasion Gated Capabilitydist/cli.cjs
HighTrigger Reachable Command Output Exfiltrationdist/cli.cjs
HighTrigger Reachable Persistencedist/cli.cjs
MediumDynamic Requiredist/cli.cjs
MediumNetwork
MediumEnvironment Vars
MediumInstall Persistencedist/cli.cjs
Medium
Affected versions and remediation
This report applies to resend-cli@2.27.0.
See all versions of resend-cli for other recorded verdicts.
- Review the evidence and your use of resend-cli@2.27.0 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.