CVE-2026-30921

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.

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.

Summary 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 appears to be a separate issue from the previously published `node:vm(GHSA-h343-gg57-2q67)` breakout advisory because the root cause here is exposure of a dangerous host capability object to untrusted code, not prototype-chain access to `process`. ## Details A normal project member can create or edit monitors and monitor tests: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Models/DatabaseModels/Monitor.ts#L45-L78 - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Models/DatabaseModels/MonitorTest.ts#L27-L60 The dashboard exposes a Playwright code editor for Synthetic Monitors and allows the user to queue a test run: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/App/FeatureSet/Dashboard/src/Components/Form/Monitor/MonitorStep.tsx#L861-L918 - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/App/FeatureSet/Dashboard/src/Components/Form/Monitor/MonitorTest.tsx#L66-L84 The probe worker polls queued monitor tests and executes them: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Jobs/Monitor/FetchMonitorTest.ts#L55-L85 For `MonitorType.SyntheticMonitor`, the user-controlled `customCode` is passed into `SyntheticMonitor.execute(...)`: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Utils/Monitors/Monitor.ts#L323-L338 `SyntheticMonitor.execute(...)` then runs that code through `VMRunner.runCodeInNodeVM(...)` and injects the live Playwright `browser` and `page` objects into the VM context: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Utils/Monitors/MonitorTypes/SyntheticMonitor.ts#L156-L168 `VMRunner.runCodeInNodeVM(...)` creates a Node `vm` context and exposes host objects into it, including the additional context objects: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Server/Utils/VM/VMRunner.ts#L323-L405 The proxy wrapper blocks only a small set of property names and still forwards normal method calls with the real host `this` binding. Because of that, untrusted monitor code can still use legitimate Playwright methods on the injected `browser` object. That is enough for code execution because Playwright's `Browser` exposes `browserType()`, and `BrowserType.launch()` accepts attacker-controlled process launch options such as `executablePath`, `args`, and `ignoreDefaultArgs`. An attacker can therefore cause the probe to spawn an arbitrary executable. Even if Playwright later errors because the spawned process is not a real browser, the command has already executed. This same execution path is also used for normal scheduled monitors, not only one-shot monitor tests: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Jobs/Monitor/FetchList.ts#L110-L121 As a result, the issue can be abused either as a one-shot RCE via `Test Monitor` or as a persistent scheduled RCE by saving a malicious Synthetic Monitor. ### PoC 1. Log in as any user with normal project membership. 2. Go to `Monitors -> Create New Monitor`. 3. Select `Synthetic Monitor`. 4. In `Playwright Code`, paste the following script: ```javascript const HostFunction = Object.getOwnPropertyDescriptor(console, "log").value.constructor; return { data: { node: HostFunction('return process.version')(), cwd: HostFunction('return process.cwd()')(), id: HostFunction( 'return process.getBuiltinModule("child_process").execSync("id").toString()' )(), }, }; ``` 5. Select any one browser type, for example `Chromium`. 6. Select any one screen type, for example `Desktop`. 7. Set retry count to `0`. 8. Click `Test Monitor` and choose a probe. Expected result: - the monitor execution succeeded and in the `Show More Details` the command output is shown. <img width="899" height="249" alt="image" src="https://github.com/user-attachments/assets/98ebd26f-431b-438e-9459-7deeebf97b18" /> ### Impact This is a server-side `Remote Code Execution` issue affecting the probe component. Who is impacted: - any OneUptime deployment where an attacker can obtain ordinary project membership - environments where the probe has access to internal services, secrets, Kubernetes metadata, database credentials, proxy credentials, or other cluster-local trust relationships

Summary 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 appears to be a separate issue from the previously published `node:vm(GHSA-h343-gg57-2q67)` breakout advisory because the root cause here is exposure of a dangerous host capability object to untrusted code, not prototype-chain access to `process`. ## Details A normal project member can create or edit monitors and monitor tests: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Models/DatabaseModels/Monitor.ts#L45-L78 - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Models/DatabaseModels/MonitorTest.ts#L27-L60 The dashboard exposes a Playwright code editor for Synthetic Monitors and allows the user to queue a test run: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/App/FeatureSet/Dashboard/src/Components/Form/Monitor/MonitorStep.tsx#L861-L918 - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/App/FeatureSet/Dashboard/src/Components/Form/Monitor/MonitorTest.tsx#L66-L84 The probe worker polls queued monitor tests and executes them: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Jobs/Monitor/FetchMonitorTest.ts#L55-L85 For `MonitorType.SyntheticMonitor`, the user-controlled `customCode` is passed into `SyntheticMonitor.execute(...)`: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Utils/Monitors/Monitor.ts#L323-L338 `SyntheticMonitor.execute(...)` then runs that code through `VMRunner.runCodeInNodeVM(...)` and injects the live Playwright `browser` and `page` objects into the VM context: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Utils/Monitors/MonitorTypes/SyntheticMonitor.ts#L156-L168 `VMRunner.runCodeInNodeVM(...)` creates a Node `vm` context and exposes host objects into it, including the additional context objects: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Common/Server/Utils/VM/VMRunner.ts#L323-L405 The proxy wrapper blocks only a small set of property names and still forwards normal method calls with the real host `this` binding. Because of that, untrusted monitor code can still use legitimate Playwright methods on the injected `browser` object. That is enough for code execution because Playwright's `Browser` exposes `browserType()`, and `BrowserType.launch()` accepts attacker-controlled process launch options such as `executablePath`, `args`, and `ignoreDefaultArgs`. An attacker can therefore cause the probe to spawn an arbitrary executable. Even if Playwright later errors because the spawned process is not a real browser, the command has already executed. This same execution path is also used for normal scheduled monitors, not only one-shot monitor tests: - https://github.com/OneUptime/oneuptime/blob/8e90f451426b160718bdd1796b68c5ec15318101/Probe/Jobs/Monitor/FetchList.ts#L110-L121 As a result, the issue can be abused either as a one-shot RCE via `Test Monitor` or as a persistent scheduled RCE by saving a malicious Synthetic Monitor. ### PoC 1. Log in as any user with normal project membership. 2. Go to `Monitors -> Create New Monitor`. 3. Select `Synthetic Monitor`. 4. In `Playwright Code`, paste the following script: ```javascript const HostFunction = Object.getOwnPropertyDescriptor(console, "log").value.constructor; return { data: { node: HostFunction('return process.version')(), cwd: HostFunction('return process.cwd()')(), id: HostFunction( 'return process.getBuiltinModule("child_process").execSync("id").toString()' )(), }, }; ``` 5. Select any one browser type, for example `Chromium`. 6. Select any one screen type, for example `Desktop`. 7. Set retry count to `0`. 8. Click `Test Monitor` and choose a probe. Expected result: - the monitor execution succeeded and in the `Show More Details` the command output is shown. <img width="899" height="249" alt="image" src="https://github.com/user-attachments/assets/98ebd26f-431b-438e-9459-7deeebf97b18" /> ### Impact This is a server-side `Remote Code Execution` issue affecting the probe component. Who is impacted: - any OneUptime deployment where an attacker can obtain ordinary project membership - environments where the probe has access to internal services, secrets, Kubernetes metadata, database credentials, proxy credentials, or other cluster-local trust relationships

OneUptime es una solución para monitorear y gestionar servicios en línea. Antes de la versión 10.0.20, los Monitores Sintéticos de OneUptime permiten a usuarios de proyecto con bajos privilegios enviar código Playwright personalizado que se ejecuta en el servicio oneuptime-probe. En la implementación actual, este código no confiable se ejecuta dentro de la vm de Node y se le otorgan objetos Playwright de host en vivo como navegador y página. Esto crea una primitiva RCE del lado del servidor distinta: el atacante no necesita el clásico escape de sandbox this.constructor.constructor(...). En su lugar, el atacante puede usar directamente el objeto navegador de Playwright inyectado para alcanzar browser.browserType().launch(...) y generar un ejecutable arbitrario en el host/contenedor de la sonda. Esta vulnerabilidad se corrige en la versión 10.0.20.