CVE-2026-42552: Flight PHP sensitive information disclosure in default error handler

CVE-2026-42552 · Severity: high · CVSS 7.5 · Published 2026-05-13

Flight, a lightweight PHP web framework, contains a flaw where it automatically displays detailed error information to any user when a system error occurs. This information includes private server file paths, internal code structures, and potentially sensitive data like database passwords or API keys if they are included in error messages. Attackers can use these details to better understand the server's internal setup and launch more sophisticated attacks against the application.

Technologies: FlightPHP Flight, flightphp/core (Packagist). Vendors: FlightPHP, Packagist.

Quick answers

Is CVE-2026-42552 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-42552 being exploited in the wild.
How severe is CVE-2026-42552?
High severity, with a CVSS score of 7.5, published 13 May 2026.
Which products and versions are affected?
FlightPHP Flight < 3.18.1; flightphp/core (Packagist) < 3.18.1, ECOSYSTEM:introduced=0,fixed=3.18.1.
Is there a fix for CVE-2026-42552?
Yes. flightphp/core (Packagist): upgrade to 3.18.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-42552 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-42552?
Check whether you run FlightPHP Flight or flightphp/core (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • flightphp/core (Packagist): upgrade to 3.18.1 or later
    composer require flightphp/core:^3.18.1

Technical details

A sensitive information disclosure vulnerability exists in the Flight PHP framework's default error handler, Engine::_error(). Prior to version 3.18.1, the framework lacked 'debug gating,' meaning it would unconditionally write the full exception message, exception code, and stack trace (including absolute filesystem paths) directly into HTTP 500 responses. This behavior occurs in production environments, allowing unauthenticated remote attackers to trigger errors and harvest internal metadata. This leaked data can include interpolated secrets (like credentials in exception strings) and full module structures, which can be used to weaponize other vulnerabilities such as Local File Inclusion (LFI). The issue is resolved in version 3.18.1 by introducing a 'flight.debug' setting that defaults to false.

Affected products

  • flightphp Flight < 3.18.1

Identifiers

  • CVE-2026-42552
  • GHSA-qrch-52m5-vv85

Timeline

  • 2026-04-29: advisory: GitHub Security Advisory published
  • 2026-05-13: disclosed: CVE published to NVD

References

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