GHSA-89cp-7p28-jffg
Kirby: Access to files of top-level drafts is not protected by permissions
Blast Radius
getkirby/cms🐘getkirby/cmsReal-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
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 and Kirby 5.4.4. Please update to one of these or a later version 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | all versions | 4.9.4 |
| 🐘Packagist | getkirby/cms | ≥ 5.0.0-alpha.1&&< 5.4.4 | 5.4.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms. 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 getkirby/cms to 4.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-89cp-7p28-jffg 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 GHSA-89cp-7p28-jffg 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 GHSA-89cp-7p28-jffg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-89cp-7p28-jffg in your dependencies?
O3 detects GHSA-89cp-7p28-jffg across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.