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OpenremoteApplication

CVE-2026-39842

CRITICAL · 9.9 CVSS v3.1 Published 2026-04-15
Fix available
A fix is available. Upgrade to 1.22.0 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
OpenRemote is an open-source IoT platform. Versions 1.21.0 and below contain two interrelated expression injection vulnerabilities in the rules engine that allow arbitrary code execution on the server. The JavaScript rules engine executes user-supplied scripts via Nashorn's ScriptEngine.eval() without sandboxing, class filtering, or access restrictions, and the authorization check in RulesResourceImpl only restricts Groovy rules to superusers while leaving JavaScript rules unrestricted for any user with the write:rules role. Additionally, the Groovy rules engine has a GroovyDenyAllFilter security filter that is defined but never registered, as the registration code is commented out, rendering the SandboxTransformer ineffective for superuser-created Groovy rules. A non-superuser attacker with the write:rules role can create JavaScript rulesets that execute with full JVM access, enabling remote code execution as root, arbitrary file read, environment variable theft including database credentials, and complete multi-tenant isolation bypass to access data across all realms. This issue has been fixed in version 1.22.0.

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

OpenRemote IoT platform versions 1.21.0 and below contains two expression injection vulnerabilities in the rules engine. The JavaScript rules engine executes user-supplied scripts via Nashorn's ScriptEngine.eval() without sandboxing, and the authorization check only restricts Groovy rules to superusers while JavaScript rules remain unrestricted for any user with write:rules role. Additionally, the GroovyDenyAllFilter security filter is defined but never registered, rendering SandboxTransformer ineffective.

MitigationUpgrade to OpenRemote version 1.22.0 or later. Until then, revoke write:rules role from non-superusers and disable the rules engine entirely if possible.

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
OpenremoteApplication
Affected:< 1.22.0

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. Identify installed OpenRemote version
    Check the OpenRemote version file or startup logs for the version number. Common locations include the docker-compose.yml, helm values, or the admin console About page.
    Affected if The installed version is 1.21.0 or below (any version < 1.22.0)
  2. Verify rules engine is in use
    Check if any rules are defined in the OpenRemote system. Look for JavaScript or Groovy rule files in the data directory, or check the Rules section in the OpenRemote Manager UI.
    Affected if Rules (especially JavaScript rules) are defined and active in the system
  3. Confirm write:rules role assignments
    Review user role assignments in OpenRemote's identity management. Check which users or clients have the write:rules permission enabled.
    Affected if Any non-superuser account possesses the write:rules role
  4. Detect JavaScript rule definitions
    Search the OpenRemote data directory or database for JavaScript-based rules. Inspect any .js rule files or entries in the rules table that use JavaScript/Nashorn scripting.
    Affected if JavaScript rules exist in the system configuration
  5. Check GroovyDenyAllFilter registration
    Examine the OpenRemote configuration files (typically in the OR object or startup configuration) for whether GroovyDenyAllFilter is registered as a security filter in the rules engine pipeline.
    Affected if GroovyDenyAllFilter is defined but not registered in the filter chain (the filter exists in code but is not activated)

You are affected if running any version below 1.22.0 where the rules engine is enabled and users with the write:rules role (including non-superusers) can define JavaScript rules.

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 1.22.0 or later
Fixed in 1.22.0
Interim mitigation

Upgrade to OpenRemote version 1.22.0 or later. Until then, revoke write:rules role from non-superusers and disable the rules engine entirely if possible.

Recommended fix High confidence

1.22.0

  1. 1. Create a complete backup of your current OpenRemote installation including database, configuration files, and all user data.
  2. 2. Review the OpenRemote 1.22.0 release notes and migration guide for any configuration changes required.
  3. 3. Stop the running OpenRemote services.
  4. 4. Upgrade OpenRemote to version 1.22.0 following the official installation/upgrade documentation.
  5. 5. Verify that the JavaScript rules engine now has proper sandboxing and access restrictions enabled.
  6. 6. Confirm that the GroovyDenyAllFilter security filter is properly registered and active.
  7. 7. Test that the authorization checks correctly restrict JavaScript rules to superusers only.
  8. 8. Restart OpenRemote services and verify normal operation.
Caveat Review 1.22.0 release notes; while primarily a security fix, minor configuration or API changes may exist

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

Fix this in Openremote Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA5.0 h
33.0 hours of engineering $5,760
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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-2026-39842 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