CVE-2026-44174: Getkirby/cms Kirby CMS Has An Arbitrary Vulnerability

HIGH
Advisory Identifier: GHSA-86rh-h242-j8xp
CWE-470
Published
Advisory Summary

CVE-2026-44174 is a HIGH kirby cms has an arbitrary vulnerability (CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')) affecting Getkirby/cms libraries in the Packagist ecosystem. The issue involves kirby cms has an arbitrary method call via rest api search and collection query endpoints. Remediation is available by upgrading affected packages to version 4.9.1, 5.4.1.

CVE-2026-44174 at a Glance

CVE Identifier CVE-2026-44174
GHSA Identifier GHSA-86rh-h242-j8xp
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
Affected Product Getkirby/cms
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-44174

To remediate this vulnerability, upgrade all affected Getkirby/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

getkirby/cms fixed: 4.9.1
Upgrade getkirby/cms to 4.9.1
getkirby/cms fixed: 5.4.1
Upgrade getkirby/cms to 5.4.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for getkirby/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-44174, inspect your project dependencies for Getkirby/cms:

inspect dependencies for getkirby/cms

Analyze the terminal output to locate any version of Getkirby/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.9.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection'), where the product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code. In Getkirby/cms, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### TL;DR This vulnerability affects all Kirby sites that might have potential attackers in the group of authenticated Panel users. **This vulnerability is of high severity for affected sites and has a high real-world impact.** ---- ### Introduction Arbitrary method call is a type of arbitrary code execution. It is a vulnerability that allows attackers to run any commands or code of the attacker's choice on a target machine or in a target process. Depending on the set of accessible methods, this can lead to disclosure of sensitive information or to unintended and malicious write actions. ### Affected components Kirby's data model is made up of model objects that are contained in collection objects. These collections can be queried with methods such as `$collection->filter()`, `$collection->sort()`, `$collection->group()`, `$collection->pluck()` and `$collection->findBy()`. Each of these methods allows to query the models contained in the collection by any accessible model attribute (field or method). Kirby also provides endpoints in its REST API that allow to search through users or through children and files of the site or of a particular page. These endpoints allow the `search`, `not`, `filter` and `sort` queries as well as options to paginate the result. The same kind of queries can also be provided to API collections such as `/<site|page|user>/blueprints`, `/<site|page>/children`, `/<model>/files`, `/languages`, `/roles`, `/translations`, `/users` and `/<user>/roles`. ### Impact In affected releases, Kirby did not validate the model attributes that were used in the collection queries. This allowed attackers to include arbitrary model methods in their queries. This includes methods with sensitive data such as `password()` (disclosing the password hash) or `root()` (disclosing the absolute filesystem path on the server) as well as methods that perform impactful actions such as `loginPasswordless()` (causing a privilege escalation to another user) or `delete()` (deleting all queried models in one go if the authenticated user has appropriate permissions). ### Patches The problem has been patched in [Kirby 4.9.1](https://github.com/getkirby/kirby/releases/tag/4.9.1) and [Kirby 5.4.1](https://github.com/getkirby/kirby/releases/tag/5.4.1). Please update to one of these or a [later version](https://github.com/getkirby/kirby/releases) to fix the vulnerability. In all of the mentioned releases, Kirby has added a blocklist of sensitive model methods that should not be called during collection operations and limited the query options for the affected endpoints to search and pagination. ### Credits Kirby thanks @mojamojam for responsibly reporting the identified issue.

CVE-2026-44174 Affected Getkirby/cms Versions

2 component(s)
Fixed Versions:
4.9.15.4.1
Product / Package Ecosystem Affected Versions Fixed Version
getkirby/cms
Packagist
< 4.9.1
4.9.1
getkirby/cms
Packagist
≥ 5.0.0
< 5.4.1
5.4.1

References

Frequently Asked Questions

What is CVE-2026-44174?
CVE-2026-44174 is a security vulnerability in Getkirby/cms involving Kirby CMS has an Arbitrary Method Call via REST API Search and Collection Query Endpoints under CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection').
Which Getkirby/cms versions are affected?
Affected versions include releases prior to 4.9.1, 5.4.1 across affected packages: getkirby/cms.
What version fixes CVE-2026-44174?
Upgrading to 4.9.1, 5.4.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is getkirby/cms affected?
Yes, getkirby/cms is affected in releases prior to 4.9.1, 5.4.1. Upgrade your dependency to 4.9.1, 5.4.1 or later.
What CWE is associated with CVE-2026-44174?
CVE-2026-44174 is classified under CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') (The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.).
How can I check Packagist dependencies for CVE-2026-44174?
Run the dependency tree command: 'inspect dependencies for getkirby/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-86rh-h242-j8xp",
  "modified" : "2026-05-26T23:47:17Z",
  "published" : "2026-05-26T23:47:17Z",
  "aliases" : [ "CVE-2026-44174" ],
  "summary" : "Kirby CMS has an Arbitrary Method Call via REST API Search and Collection Query Endpoints",
  "details" : "### TL;DR\n\nThis vulnerability affects all Kirby sites that might have potential attackers in the group of authenticated Panel users.\n\n**This vulnerability is of high severity for affected sites and has a high real-world impact.**\n\n----\n\n### Introduction\n\nArbitrary method call is a type of arbitrary code execution. It is a vulnerability that allows attackers to run any commands or code of the attacker's choice on a target machine or in a target process.\n\nDepending on the set of accessible methods, this can lead to disclosure of sensitive information or to unintended and malicious write actions.\n\n### Affected components\n\nKirby's data model is made up of model objects that are contained in collection objects. These collections can be queried with methods such as `$collection->filter()`, `$collection->sort()`, `$collection->group()`, `$collection->pluck()` and `$collection->findBy()`. Each of these methods allows to query the models contained in the collection by any accessible model attribute (field or method).\n\nKirby also provides endpoints in its REST API that allow to search through users or through children and files of the site or of a particular page. These endpoints allow the `search`, `not`, `filter` and `sort` queries as well as options to paginate the result. The same kind of queries can also be provided to API collections such as `/<site|page|user>/blueprints`, `/<site|page>/children`, `/<model>/files`, `/languages`, `/roles`, `/translations`, `/users` and `/<user>/roles`.\n\n### Impact\n\nIn affected releases, Kirby did not validate the model attributes that were used in the collection queries. This allowed attackers to include arbitrary model methods in their queries. This includes methods with sensitive data such as `password()` (disclosing the password hash) or `root()` (disclosing the absolute filesystem path on the server) as well as methods that perform impactful actions such as `loginPasswordless()` (causing a privilege escalation to another user) or `delete()` (deleting all queried models in one go if the authenticated user has appropriate permissions).\n\n### Patches\n\nThe problem has been patched in [Kirby 4.9.1](https://github.com/getkirby/kirby/releases/tag/4.9.1) and [Kirby 5.4.1](https://github.com/getkirby/kirby/releases/tag/5.4.1). Please update to one of these or a [later version](https://github.com/getkirby/kirby/releases) to fix the vulnerability.\n\nIn all of the mentioned releases, Kirby has added a blocklist of sensitive model methods that should not be called during collection operations and limited the query options for the affected endpoints to search and pagination.\n\n### Credits\n\nKirby thanks @mojamojam for responsibly reporting the identified issue.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "getkirby/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.9.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.9.0"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "getkirby/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0"
      }, {
        "fixed" : "5.4.1"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.4.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/security/advisories/GHSA-86rh-h242-j8xp"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/getkirby/kirby"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/releases/tag/4.9.1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/releases/tag/5.4.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-470" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-26T23:47:17Z",
    "nvd_published_at" : null
  }
}