Kirby CMS has pre-authentication path traversal and PHP file inclusion during user lookupGHSA-9hx7-c53c-v6x8
GHSA-9hx7-c53c-v6x8 is a Path Traversal vulnerability in getkirby/cms. A fix is available for getkirby/cms — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-9hx7-c53c-v6x8.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
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 all Kirby sites on Kirby 5.3.0-5.4.0 and is independent from setup conditions and authentication.
This vulnerability is of high severity for all Kirby sites.
Introduction
Path traversal is a type of attack that allows to access arbitrary filesystem paths. By using special elements such as .. and / separators, attackers can escape outside of the restricted location to access files or directories that are elsewhere on the system. One of the most common special elements is the ../ sequence, which in most modern operating systems is interpreted as the parent directory of the current location. Path traversal can give attackers information about the filesystem and directory structure on the server and can lead to additional attacks depending on the nature of the accessible files and directories.
PHP file inclusion is a type of attack that allows to load and execute PHP files on the server that are not intended for direct inclusion. Depending on the logic inside the PHP files, this can lead to disclosure of sensitive information or unintended, malicious actions.
Affected components
Kirby's Users collection received a performance improvement in Kirby 5.3.0. Starting in this release, Kirby loads user objects lazily when they are first needed. Users are queried by their user ID, which is then used to look up the user's account directory in the site/accounts directory.
This applies to the authentication API (accessible to unauthenticated requests), the users API (accessible to authenticated users only) as well as to other places that use $users->find() to look up an individual user with a request-provided email or user ID.
Impact
In affected releases, Kirby did not correctly validate the provided user ID, causing a path traversal vulnerability. This vulnerability results in the following impact:
- Arbitrary PHP file inclusion of files with the filename
index.php(e.g. the main PHP files of plugins), the impact of which depends on the contents and logic inside the includable files. - Probing of the existence of arbitrary directories on the server, which can allow attackers to fingerprint the server and site setup, including installed plugins and the content structure.
Patches
The problem has been patched in Kirby 5.4.1. Please update to this or a later version to fix the vulnerability.
In the mentioned release, Kirby has added additional checks to the user lookup that ensure that the provided user ID only contains valid characters and that the resulting path to the account directory is contained in the site/accounts directory.
Credits
Kirby thanks @offset for responsibly reporting the identified issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | ≥ 5.3.0&&< 5.4.1 | 5.4.1composer require getkirby/cms:^5.4.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update getkirby/cms to 5.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9hx7-c53c-v6x8 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
How to detect GHSA-9hx7-c53c-v6x8
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id ghsa-9hx7-c53c-v6x8 -u https://target- Template
- Kirby CMS 5.3.0-5.4.0 - Path Traversal
- Severity
- high
- Impact
- Attackers can include arbitrary PHP files and fingerprint server directories, potentially leading to code execution or information disclosure.
- Remediation
- Update to version 5.4.1 or later.
Template by ProjectDiscovery nuclei-templates (str4k3r), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is GHSA-9hx7-c53c-v6x8 in your dependencies?
Find it across Packagist, including transitive dependencies.