CVE-2026-30921 CRITICAL

CVE-2026-30921: OneUptime Synthetic Monitor RCE via exposed Playwright browser object

Vendor Oneuptime
Product oneuptime
Weakness CWE-749
Published March 9, 2026
Last update March 10, 2026

CVSS base score

10.0/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

OneUptime is a solution for monitoring and managing online services. Prior to 10.0.20, OneUptime Synthetic Monitors allow low-privileged project users to submit custom Playwright code that is executed on the oneuptime-probe service. In the current implementation, this untrusted code is run inside Node's vm and is given live host Playwright objects such as browser and page. This creates a distinct server-side RCE primitive: the attacker does not need the classic this.constructor.constructor(...) sandbox escape. Instead, the attacker can directly use the injected Playwright browser object to reach browser.browserType().launch(...) and spawn an arbitrary executable on the probe host/container. This vulnerability is fixed in 10.0.20.

Key dates

02Disclosure timeline

March 9, 2026 CVE published
March 10, 2026 Record updated