Summary
Kirby: System path exposure from error messages in the REST API
TL;DR
This vulnerability affects all Kirby sites that have not disabled the REST API with the 'api' => false option.
It was possible to trigger a PHP error in the API backend that would expose the full filesystem path of the Kirby installation on the server. This could be used to guess the default content.salt or prepare specialized attacks.
Introduction
An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. Using other weaknesses, an attacker could cause errors to occur; the response to these errors can reveal detailed system information, along with other impacts. An attacker can use messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. A product may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.
Affected components
Kirby's REST API at /api returns JSON data for each request. If an error occurs during processing of the request, a special error handler converts this error to JSON data that API frontends can handle.
The returned data for errors depends on the debugging mode. If the debug option is enabled, the JSON data contains fields for the path and line of the affected file, the internal exception class and the API route that caused the error. This data is omitted from error responses in production (when the debug option is disabled).
Credits
Thanks to Peter Levashov (@petersevera) for responsibly reporting the identified issue.
Impact
Some internal errors may contain sensitive information in the error message itself. This is often the case with PHP errors.
In affected releases, the REST API error handler did not sanitize error messages for sensitive information.
This exposed system information like the full source path to external API users, including users without authentication. This could be used to guess the default content.salt or prepare specialized attacks.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The problem has been patched in Kirby 4.9.5 and Kirby 5.5.2. Please update to one of these or a later version to fix the vulnerability.
In all of the mentioned releases, Kirby has hardened the API error handler to only expose full error messages for exceptions in the Kirby\Exception namespace. All other errors are only exposed in debug mode (with disguised paths, keeping only the paths relative to the Kirby installation). Outside of debug mode, general exceptions and PHP errors are replaced with a generic error message.
Frequently Asked Questions
- What is CVE-2026-69127? CVE-2026-69127 is a medium-severity security vulnerability in getkirby/cms (composer), affecting versions <= 4.9.4. It is fixed in 4.9.5, 5.5.2.
- Which versions of getkirby/cms are affected by CVE-2026-69127? getkirby/cms (composer) versions <= 4.9.4 is affected.
- Is there a fix for CVE-2026-69127? Yes. CVE-2026-69127 is fixed in 4.9.5, 5.5.2. Upgrade to this version or later.
- Is CVE-2026-69127 exploitable, and should I be worried? Whether CVE-2026-69127 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-69127 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-69127?
- Upgrade
getkirby/cmsto 4.9.5 or later - Upgrade
getkirby/cmsto 5.5.2 or later
- Upgrade