@mastra/agent-browser (npm) · Malicious Code
Affects @mastra/agent-browserSource GCVE Database
Malicious package : remove @mastra/agent-browser and rotate any secrets on hosts that installed it.
Data as of 11 Jul 2026, 09:43 UTC
Malicious package
Published to npm · OSV MAL-2026-5996
What to do
Remove @mastra/agent-browser from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npm@mastra/agent-browser | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (49ba6a41e7e43733a8334968ce740af8771208c66c7529d9f4319bd62e39601d) @mastra/agent-browser@0.3.2 declares a dependency on 'easy-day-js@^1.11.21' in package.json, but the package's own compiled code in dist/index.js never imports or references easy-day-js (only @mastra/core, agent-browser, and zod are used). The dependency name resembles the popular 'dayjs' library and pulling it in at install time means every installer of @mastra/agent-browser also fetches and executes whatever easy-day-js contains. The wrapper package's own code shows no install hooks, no obfuscation, and no exfiltration behavior, so the installer-side risk depends entirely on the contents of easy-day-js. Routing to human review so the transitive can be evaluated and, if malicious, both packages handled together. ## Source: ghsa-malware (f47e1be40751417e2e8e62b23068d7f74df247fc0c2b47cdf0b7ddb9733ca2f4) Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.