---
title: "CVE-2026-30957: OneUptime has Synthetic Monitor RCE via exposed Playwright browser object"
url: https://erroneo.us/security/cve/CVE-2026-30957/
description: "CVE-2026-30957 (@oneuptime/common (npm)): OneUptime is a solution for monitoring and managing online services. Prior to 10.0.21, OneUptime Synthetic…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-10
date_modified: 2026-03-10
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-30957"
kev: false
cvss: 10
epss: 0.01198
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 1.2% , percentile 68: FIRST’s model estimates a 1.2% chance of exploitation activity in the next 30 days, higher than 68% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes @oneuptime/common (npm) < 10.0.21, fixed in 10.0.21 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- npm `@oneuptime/common` < 10.0.21 → fixed: 10.0.21

## Affected products (CVE record)

- OneUptime oneuptime: < 10.0.21

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 1.20% probability of exploitation activity in the next 30 days; percentile 68.

## Sources

- [GitHub Advisory GHSA-jw8q-gjvg-8w4q](https://github.com/advisories/GHSA-jw8q-gjvg-8w4q)
- [CVE.org record CVE-2026-30957](https://www.cve.org/CVERecord?id=CVE-2026-30957)
- [NVD entry CVE-2026-30957](https://nvd.nist.gov/vuln/detail/CVE-2026-30957)
- [github.com](https://github.com/OneUptime/oneuptime/security/advisories/GHSA-jw8q-gjvg-8w4q)
- [github.com](https://github.com/OneUptime/oneuptime/releases/tag/10.0.21)

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Source page: https://erroneo.us/security/cve/CVE-2026-30957/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt