GHSA-cw7v-45wm-mcf2
Withdrawn Advisory: Kirby CMS has Persistent DoS via Malformed Image Upload
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Packagist | getkirby/cms | < 5.2.0-rc.1 | 5.2.0-rc.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
### Duplicate Advisory
This advisory has been withdrawn because it is been determined to not be a vulnerability. This link is maintained to preserve external references.
### Original Description
## Summary
Kirby CMS through version 5.1.4 allows an authenticated user with Editor permissions to cause a persistent Denial of Service (DoS) via a malformed image upload.
## Details
The vulnerability is caused by improper validation of the return value of PHP's `getimagesize()` function. When a malformed file is uploaded with a valid image extension (e.g., `.jpg`), the function returns `false` instead of an expected array.
The application fails to handle this condition properly and proceeds with image processing, resulting in a fatal `TypeError`. This leads to persistent application crashes when the affected file is accessed.
## Impact
- Persistent Denial of Service (DoS)
- Affected pages return HTTP 500 errors
- Requires manual removal of the malformed file to restore functionality
- Exploitable by authenticated users with Editor permissions
## Identifiers
- CVE-2026-29905
## Resources
- https://github.com/github/advisory-database/pull/7503
- https://github.com/Stalin-143/CVE-2026-29905
- https://github.com/getkirby/kirby/releases/tag/5.2.0-rc.1
- https://www.cve.org/CVERecord?id=CVE-2026-29905
References
External links from the advisory. They lead to third-party sites.
- https://github.com/Stalin-143/CVE-2026-29905/security/advisories/GHSA-cw7v-45wm-mcf2
- https://nvd.nist.gov/vuln/detail/CVE-2026-29905
- https://github.com/github/advisory-database/pull/7503
- https://drive.google.com/file/d/1MwvvSYIwnC8kOIzjycGMQZw4d2K2ef8h/view?usp=sharing
- https://github.com/Stalin-143/CVE-2026-29905
- https://github.com/getkirby/kirby/releases/tag/5.2.0-rc.1