CVE-2026-42552
HIGHCVE-2026-42552 is a high-severity (CVSS 7.5) vulnerability in flightphp/core. O3 Security confirms whether CVE-2026-42552 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Flight: Sensitive information disclosure via default error handler in flightphp/core
Real-World Exposure
flightphp/coreReal-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
Flight is an extensible micro-framework for PHP. Prior to 3.18.1, the default error handler Engine::_error() writes the full exception message, exception code, and stack trace (including absolute filesystem paths) directly into the HTTP 500 response, with no debug gating. Production deployments leak internal paths, any secret interpolated into an exception message, and full module structure — giving attackers primitives for chaining other weaknesses (LFI, path traversal). This vulnerability is fixed in 3.18.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | flightphp/core | all versions | 3.18.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flightphp/core. 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 flightphp/core to 3.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42552 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-2026-42552 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-2026-42552. 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-2026-42552 in your dependencies?
O3 detects CVE-2026-42552 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.