CVE-2026-42051
CVE-2026-42051 is a CWE-862 vulnerability in getkirby/cms. O3 Security confirms whether CVE-2026-42051 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Kirby: System API endpoint leaks license data and installed version to authenticated users
Real-World Exposure
getkirby/cms🐘getkirby/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Kirby is an open-source content management system. Prior to versions 4.9.0 and 5.4.0, the system API endpoint leaks license data and installed version to authenticated users. This issue has been patched in versions 4.9.0 and 5.4.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | all versions | 4.9.0 |
| 🐘Packagist | getkirby/cms | ≥ 5.0.0&&< 5.4.0 | 5.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms. 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 getkirby/cms to 4.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42051 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-2026-42051 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-2026-42051. 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-2026-42051 in your dependencies?
O3 detects CVE-2026-42051 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.