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OneuptimeApplication · Hackerbay

CVE-2026-30921

CRITICAL · 9.9 CVSS v3.1 Published 2026-03-10
Fix available
A fix is available. Upgrade to 10.0.20 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OneUptime Synthetic Monitors prior to 10.0.20 allows low-privileged project users to submit custom Playwright code that executes on the oneuptime-probe service. The code runs in Node's vm with live Playwright objects (browser, page) exposed to the untrusted code, enabling direct RCE via browser.browserType().launch() to spawn arbitrary executables on the probe host/container - no sandbox escape is required.

MitigationUpgrade to OneUptime version 10.0.20 or later. If immediate upgrade is not possible, disable or restrict low-privileged user access to the Synthetic Monitors feature and implement network isolation for probe services.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OneuptimeApplication
Affected:< 10.0.20

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed OneUptime version
    Locate the OneUptime installation and identify its version number. Common locations include: package.json in the application root, a version file, Docker image tag, or the admin dashboard About section.
    Affected if The installed version is lower than 10.0.20 (e.g., 10.0.19, 10.0.10, any 9.x version)
  2. Verify Synthetic Monitors feature status
    Access the OneUptime admin panel or configuration and determine whether the Synthetic Monitors feature is enabled for any project.
    Affected if Synthetic Monitors is enabled and the OneUptime version is below 10.0.20
  3. Review low-privileged user access to Synthetic Monitors
    Examine user role permissions and project access settings to determine if non-admin users (project users, standard users) have permissions to create or edit Synthetic Monitors.
    Affected if Low-privileged users (non-admin) have create/edit permissions on Synthetic Monitors and the version is below 10.0.20
  4. Inspect oneuptime-probe service configuration
    Locate the probe service configuration file or environment variables to confirm the probe is running and accessible to user-submitted Playwright code execution.
    Affected if The oneuptime-probe service is running and accessible, Synthetic Monitors is enabled, and version is below 10.0.20

The environment is affected if OneUptime version is below 10.0.20 AND the Synthetic Monitors feature is enabled, allowing low-privileged users to execute arbitrary code via exposed Playwright objects.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 10.0.20 or later
Fixed in 10.0.20
Interim mitigation

Upgrade to OneUptime version 10.0.20 or later. If immediate upgrade is not possible, disable or restrict low-privileged user access to the Synthetic Monitors feature and implement network isolation for probe services.

Recommended fix High confidence

OneUptime version 10.0.20

  1. Identify all OneUptime deployments running versions prior to 10.0.20
  2. Upgrade OneUptime to version 10.0.20 or later
  3. After upgrade, verify the version is 10.0.20 or higher in the OneUptime admin interface
  4. Test synthetic monitor functionality to ensure legitimate monitoring workflows still operate correctly
  5. Review any synthetic monitor configurations that may have relied on the previous behavior

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Oneuptime Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-30921 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data