What’s Vulnerable › Vulnerabilities
CVE-2026-30921: OneUptime Synthetic Monitor RCE via exposed Playwright browser object
- Severity: critical (CVSS 9.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-03-10 · updated 2026-06-17
- Weakness: CWE-749
Description
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.
Affected products
- oneuptime: before 10.0.20 — fixed in 10.0.20
How to fix
Upgrade to a fixed version: oneuptime 10.0.20. Check the vendor advisory for mitigations.
References
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