OneUptime: Synthetic Monitor RCE via exposed Playwright browser object

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-30921: 0.46% estimated exploitation activity in the next 30 days; percentile 40.13 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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: -…

Published by the source

7 Mar 2026, 02:39 UTC

Last modified by the source

10 Mar 2026, 19:01 UTC

Source last checked

26 Oct 2026, 12:43 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-4j36-39gm-8vq8

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-4j36-39gm-8vq8

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-4j36-39gm-8vq8

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# Patch Next advisory brief: CVE-2026-30921

Advisory: OneUptime: Synthetic Monitor RCE via exposed Playwright browser object
IDs: CVE-2026-30921, GHSA-4j36-39gm-8vq8
Record: https://patchnext.com/advisories/cve-2026-30921 (revision 3, source checked 26 Oct 2026, 12:43 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @oneuptime/common 10.0.20. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @oneuptime/common: affected < 10.0.20; fixed in 10.0.20

## Suggested inspection (read-only)
- `npm ls @oneuptime/common --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @oneuptime/common.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4j36-39gm-8vq8 (GitHub-reviewed advisory GHSA-4j36-39gm-8vq8 lists affected ranges: npm @oneuptime/common >=0 <10.0.20)
- Verified: https://osv.dev/vulnerability/GHSA-4j36-39gm-8vq8 (OSV record GHSA-4j36-39gm-8vq8 lists affected ranges: npm @oneuptime/common >=0 <10.0.20 (fixed))

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