SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-30921

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.

CRITICAL 9.9EPSS 0.46%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS
0.46% probability · 40th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-749
Affected
hackerbay/oneuptime
Source
security-advisories@github.com
EPSS trend
0%3%5%26 October 2026: 0.46%26 October 202626 October 2026

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.