CVE-2026-54004: Kirby Access To Files Of Top-level Vulnerability

MODERATE
Advisory Identifier: GHSA-89cp-7p28-jffg
CWE-862
Published
Advisory Summary

CVE-2026-54004 is a MODERATE access to files of top-level vulnerability (CWE-862: Missing Authorization) affecting Kirby libraries in the Packagist ecosystem. The issue involves access to files of top-level drafts is not protected by permissions. Remediation is available by upgrading affected packages to version 4.9.4, 5.4.4.

CVE-2026-54004 at a Glance

CVE Identifier CVE-2026-54004
GHSA Identifier GHSA-89cp-7p28-jffg
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-862: Missing Authorization
Affected Product Kirby
Package Ecosystem Packagist
Published Date
Last Updated

How to Fix CVE-2026-54004

To remediate this vulnerability, upgrade all affected Kirby 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: 4.9.4
Upgrade getkirby/cms to 4.9.4
getkirby/cms fixed: 5.4.4
Upgrade getkirby/cms to 5.4.4
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-2026-54004, inspect your project dependencies for Kirby:

inspect dependencies for getkirby/cms

Analyze the terminal output to locate any version of Kirby in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.9.4), 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-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In Kirby, 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 Kirby 5 sites that have the `content.fileRedirects` option enabled (set to `true` or a custom closure) as well as all Kirby 4 sites that haven't explicitly disabled this option. It was possible to access clean file URLs of top-level drafts (e.g. `/about-us/team.jpg`) without providing authentication, without being authorized to access the top-level draft page, and without providing a valid preview token. Sites on Kirby 5 using the default configuration are *not* affected by this vulnerability (the `content.fileRedirects` option is disabled by default since Kirby 5.0.0). It was also *not* possible to maliciously access clean file URLs for files stored in page drafts that are not on the top-level (such as `/blog/article/resource.pdf`). ---- ### Introduction Missing authorization allows authenticated users to perform actions they are not intended to have access to. The effects of missing authorization can include unauthorized access to sensitive information as well as unauthorized changes to content or system information. ### Affected components Clean file redirects allow visitors to access files stored in the content folder via natural URLs such as `/about-us/team.jpg` or `/blog/article/resource.pdf`. Kirby detects such requests and redirects them to the actual physical file URLs in the `media` folder. Kirby 4.8.0 introduced the `content.fileRedirects` option that allowed disabling this behavior to protect against third-party access to original source files. Kirby 5.0.0 then made the secure behavior (disabled option) the default. It is also possible to set the option to a closure to dynamically control access for each individual file. Files can be stored in pages. Pages can exist as drafts. In this draft state, the page preview is only accessible to users who are authenticated and authorized by the `pages.access` permission or to visitors who have received the direct preview URL with a valid preview token. ### Impact In affected releases, the clean file redirects didn't take access logic for drafts into account. When a file stored in a draft page was accessed via its clean file URL, Kirby immediately redirected to the physical media URL without first checking whether the draft page was accessible to the user or visitor. This only affected top-level drafts (direct children of the site) because clean file URLs currently don't work for drafts that are nested under another page. The unauthorized clean file URL redirects for files in top-level drafts can lead to disclosure of sensitive information or data, e.g., ahead of the launch of a new product or post. A successful attack requires knowledge of the full path to the draft page and file, and therefore requires knowing the full clean file URL. ### Patches The problem has been patched in [Kirby 4.9.4](https://github.com/getkirby/kirby/releases/tag/4.9.4) and [Kirby 5.4.4](https://github.com/getkirby/kirby/releases/tag/5.4.4). 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, we added an authorization check to the route that redirects clean file URLs of drafts. This route now performs the same checks as the draft preview route, i.e., it only performs the redirect if a user is logged in and has the `pages.access` permission on the draft, or if a valid preview token was provided in the request URL. ### Credits Thanks to @adamyordan for responsibly reporting the identified issue.

CVE-2026-54004 Affected Kirby Versions

2 component(s)
Fixed Versions:
4.9.45.4.4
Product / Package Ecosystem Affected Versions Fixed Version
getkirby/cms
Packagist
< 4.9.4
4.9.4
getkirby/cms
Packagist
≥ 5.0.0-alpha.1
< 5.4.4
5.4.4

References

Frequently Asked Questions

What is CVE-2026-54004?
CVE-2026-54004 is a security vulnerability in Kirby involving Access to files of top-level drafts is not protected by permissions under CWE-862: Missing Authorization.
Which Kirby versions are affected?
Affected versions include releases prior to 4.9.4, 5.4.4 across affected packages: getkirby/cms.
What version fixes CVE-2026-54004?
Upgrading to 4.9.4, 5.4.4 (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 4.9.4, 5.4.4. Upgrade your dependency to 4.9.4, 5.4.4 or later.
What CWE is associated with CVE-2026-54004?
CVE-2026-54004 is classified under CWE-862: Missing Authorization (The product does not perform an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Packagist dependencies for CVE-2026-54004?
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-89cp-7p28-jffg",
  "modified" : "2026-06-18T15:05:05Z",
  "published" : "2026-06-18T15:05:05Z",
  "aliases" : [ "CVE-2026-54004" ],
  "summary" : "Kirby: Access to files of top-level drafts is not protected by permissions",
  "details" : "### TL;DR\n\nThis vulnerability affects Kirby 5 sites that have the `content.fileRedirects` option enabled (set to `true` or a custom closure) as well as all Kirby 4 sites that haven't explicitly disabled this option.\n\nIt was possible to access clean file URLs of top-level drafts (e.g. `/about-us/team.jpg`) without providing authentication, without being authorized to access the top-level draft page, and without providing a valid preview token.\n\nSites on Kirby 5 using the default configuration are *not* affected by this vulnerability (the `content.fileRedirects` option is disabled by default since Kirby 5.0.0). It was also *not* possible to maliciously access clean file URLs for files stored in page drafts that are not on the top-level (such as `/blog/article/resource.pdf`).\n\n----\n\n### Introduction\n\nMissing authorization allows authenticated users to perform actions they are not intended to have access to.\n\nThe effects of missing authorization can include unauthorized access to sensitive information as well as unauthorized changes to content or system information.\n\n### Affected components\n\nClean file redirects allow visitors to access files stored in the content folder via natural URLs such as `/about-us/team.jpg` or `/blog/article/resource.pdf`. Kirby detects such requests and redirects them to the actual physical file URLs in the `media` folder.\n\nKirby 4.8.0 introduced the `content.fileRedirects` option that allowed disabling this behavior to protect against third-party access to original source files. Kirby 5.0.0 then made the secure behavior (disabled option) the default. It is also possible to set the option to a closure to dynamically control access for each individual file.\n\nFiles can be stored in pages. Pages can exist as drafts. In this draft state, the page preview is only accessible to users who are authenticated and authorized by the `pages.access` permission or to visitors who have received the direct preview URL with a valid preview token.\n\n### Impact\n\nIn affected releases, the clean file redirects didn't take access logic for drafts into account. When a file stored in a draft page was accessed via its clean file URL, Kirby immediately redirected to the physical media URL without first checking whether the draft page was accessible to the user or visitor. This only affected top-level drafts (direct children of the site) because clean file URLs currently don't work for drafts that are nested under another page.\n\nThe unauthorized clean file URL redirects for files in top-level drafts can lead to disclosure of sensitive information or data, e.g., ahead of the launch of a new product or post.\n\nA successful attack requires knowledge of the full path to the draft page and file, and therefore requires knowing the full clean file URL.\n\n### Patches\n\nThe problem has been patched in [Kirby 4.9.4](https://github.com/getkirby/kirby/releases/tag/4.9.4) and [Kirby 5.4.4](https://github.com/getkirby/kirby/releases/tag/5.4.4). 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, we added an authorization check to the route that redirects clean file URLs of drafts. This route now performs the same checks as the draft preview route, i.e., it only performs the redirect if a user is logged in and has the `pages.access` permission on the draft, or if a valid preview token was provided in the request URL.\n\n### Credits\n\nThanks to @adamyordan for responsibly reporting the identified issue.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "getkirby/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.9.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 4.9.3"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "getkirby/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-alpha.1"
      }, {
        "fixed" : "5.4.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.4.3"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/security/advisories/GHSA-89cp-7p28-jffg"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/getkirby/kirby"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/releases/tag/4.9.4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/getkirby/kirby/releases/tag/5.4.4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-18T15:05:05Z",
    "nvd_published_at" : null
  }
}