RCE in Hackerbay Oneuptime
CVE-2026-30887
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.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (44.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002
Affected products
- Hackerbay Oneuptime
- Oneuptime — versions < 10.0.18
Weakness classification (CWE)
References
- github.com/OneUptime/oneuptime/security/advisories/GHSA-h343-gg57-2q67 (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-30887?
- CVE-2026-30887 is a critical-severity vulnerability in Hackerbay Oneuptime, classified under Code Injection. CVSS score: 9.9/10. Published 2026-03-10.
- How severe is CVE-2026-30887?
- Critical severity. CVSS v3 base score is 9.9 out of 10.