CVE-2026-42205
HIGHCVE-2026-42205 is a high-severity (CVSS 8.8) vulnerability in avo. O3 Security confirms whether CVE-2026-42205 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Avo: Broken Access Control: Unauthorized Execution of Arbitrary Action Classes Across Resources
Real-World Exposure
avoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | avo | all versions | 3.31.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for avo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update avo to 3.31.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42205 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-42205 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-42205. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42205 in your dependencies?
O3 detects CVE-2026-42205 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.