Staging Environment: Content and features may be unstable or change without notice.
Search for vulnerabilities
Vulnerability details: VCID-n16k-n4g1-bqe4
Vulnerability ID VCID-n16k-n4g1-bqe4
Aliases CVE-2026-44177
GHSA-9hx7-c53c-v6x8
Summary Kirby CMS has pre-authentication path traversal and PHP file inclusion during user lookup ### 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](https://github.com/getkirby/kirby/releases/tag/5.4.1). Please update to this or a [later version](https://github.com/getkirby/kirby/releases) 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.
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (2)
No exploits are available.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N Found at https://github.com/getkirby/kirby
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N Found at https://github.com/getkirby/kirby/releases/tag/5.4.1
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N Found at https://github.com/getkirby/kirby/security/advisories/GHSA-9hx7-c53c-v6x8
Attack Vector (AV) Attack Complexity (AC) Attack Requirements (AT) Privileges Required (PR) User Interaction (UI) Vulnerable System Impact Confidentiality (VC) Vulnerable System Impact Integrity (VI) Vulnerable System Impact Availability (VA) Subsequent System Impact Confidentiality (SC) Subsequent System Impact Integrity (SI) Subsequent System Impact Availability (SA)

network

adjacent

local

physical

low

high

none

present

none

low

high

none

passive

active

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

high

low

none

No EPSS data available for this vulnerability.

Date Actor Action Source VulnerableCode Version
2026-06-04T17:03:03.826703+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-9hx7-c53c-v6x8/GHSA-9hx7-c53c-v6x8.json 38.6.0