dbcve.org
Improper Access ControlWeakness · CWE-284

CVE-2026-42205

HIGH · 8.8 CVSS v3.1 Published 2026-05-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
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
Avo is a framework to create admin panels for Ruby on Rails apps. Prior to version 3.31.2, a broken access control vulnerability was identified in the ActionsController of the Avo framework. Due to insecure action lookup logic, an authenticated user can execute any Action class (descendants of Avo::BaseAction) on any resource, even if the action is not registered for that specific resource. This leads to Privilege Escalation and unauthorized data manipulation across the entire application. This issue has been patched in version 3.31.2.

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

Broken access control vulnerability in Avo framework's ActionsController allows authenticated users to execute any Avo::BaseAction descendant on any resource, regardless of whether that action is registered for that resource. The insecure action lookup logic enables privilege escalation and unauthorized data manipulation across the entire application.

MitigationUpgrade Avo gem to version 3.31.2 or later to apply the patch that fixes the insecure action lookup logic.

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

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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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 Avo gem version
    Run `bundle show avo` or check the Gemfile.lock for the avo gem version entry
    Affected if Version is lower than 3.31.2 or the version cannot be determined (unknown if patched)
  2. Locate custom Avo::BaseAction descendants
    Search the codebase for classes inheriting from `Avo::BaseAction` using grep: `grep -r "Avo::BaseAction" app/` or inspect files in app/avo/actions/
    Affected if Any custom action classes exist in the application (vulnerability applies to all Avo actions)
  3. Verify action-to-resource authorization logic
    Inspect the ActionsController or action execution code for proper authorization checks. Look for code that validates whether an action is registered for the target resource before execution
    Affected if No authorization check exists that verifies the action is explicitly registered for the resource before allowing execution
  4. Test action execution on unregistered resources
    Using the application as an authenticated user, attempt to invoke an action via the Avo API/endpoints on a resource where that action is NOT registered (check routes and action definitions in app/avo/resources/)
    Affected if The action executes successfully on a resource it was not intended for, indicating the broken access control is present

The environment is affected if the Avo gem version is below 3.31.2 AND custom Avo actions exist, since the insecure action lookup allows execution on any resource regardless of registration.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Avo gem to version 3.31.2 or later to apply the patch that fixes the insecure action lookup logic.

Recommended fix High confidence

avo gem version 3.31.2 or later

  1. Locate the Gemfile in your Ruby on Rails project
  2. Find the line containing the avo gem (e.g., gem 'avo')
  3. Update the avo gem version to 3.31.2 or later: change gem 'avo', '~> x.x' to gem 'avo', '~> 3.31' or specify gem 'avo', '3.31.2'
  4. Run `bundle update avo` to update the gem
  5. Verify the installed version with `bundle list | grep avo`
  6. Restart your Rails application
  7. Test that admin panel functionality works correctly after the upgrade
Caveat Review Avo release notes between your current version and 3.31.2 for any breaking changes; minor version upgrades typically have minimal breaking changes

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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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-2026-42205 in production — separate from our analysis above.

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