CVE-2026-30887: Hackerbay Oneuptime

Critical severity, CVSS 9.9. EPSS: 0.6% chance of exploitation in the next 30 days.

OneUptime is a solution for monitoring and managing online services. Prior to 10.0.18, OneUptime allows project members to run custom Playwright/JavaScript code via Synthetic Monitors to test websites. However, the system executes this untrusted user code inside the insecure Node.js vm module. By leveraging a standard prototype-chain escape (this.constructor.constructor), an attacker can bypass the sandbox, gain access to the underlying Node.js process object, and execute arbitrary system commands (RCE) on the oneuptime-probe container. Furthermore, because the probe holds database/cluster credentials in its environment variables, this directly leads to a complete cluster compromise. This vulnerability is fixed in 10.0.18.

Affected products

• Hackerbay Oneuptime: before 10.0.18 (fixed in 10.0.18)

Published 2026-03-10. Last modified 2026-06-17.