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Kirby: Access to files of top-level drafts is not protected by permissions

Moderate severity GitHub Reviewed Published Jun 17, 2026 in getkirby/kirby • Updated Jun 18, 2026

Package

composer getkirby/cms (Composer)

Affected versions

<= 4.9.3
>= 5.0.0-alpha.1, <= 5.4.3

Patched versions

4.9.4
5.4.4

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.

References

@bastianallgeier bastianallgeier published to getkirby/kirby Jun 17, 2026
Published to the GitHub Advisory Database Jun 18, 2026
Reviewed Jun 18, 2026
Last updated Jun 18, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
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

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(41st percentile)

Weaknesses

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

CVE ID

CVE-2026-54004

GHSA ID

GHSA-89cp-7p28-jffg

Source code

Credits

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