Vulnerability · Published Aug 31, 2026 · Assigned by GitHub_M
CVE-2026-75592Kirby: Access to image files outside of the site root via path traversal in the media handling
Medium 6.9
In plain English
A medium-severity path traversal in kirby from getkirby. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Kirby is an open-source content management system. Prior to 4.9.5 and 5.5.2, depending on the release line, Kirby's media handler used incomplete filesystem containment checks in src/Filesystem/Dir.php and src/Filesystem/F.php through Kirby\Filesystem\Dir::realpath() and Kirby\Filesystem\F::realpath(). The checks accepted a sibling directory whose path shared the intended root's string prefix, such as /var/www/site2 next to /var/www/site, because they did not require an exact match or a DIRECTORY_SEPARATOR boundary. A remote attacker could use Kirby\Cms\Media::thumb() to create and access thumbnails from image files in a PHP-readable sibling directory when that directory contained a valid .json thumbnail job file, potentially exposing staging sites, backups, or other internal sites and deleting the job file during processing. This issue is fixed in versions 4.9.5 and 5.5.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | getkirby/cms | 4.9.5 | GHSA-6j4c-mgqr-qv76 |
| Packagist | getkirby/cms | 5.5.2 | GHSA-6j4c-mgqr-qv76 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
References
- https://github.com/getkirby/kirby/security/advisories/GHSA-6j4c-mgqr-qv76 x_refsource_CONFIRM
- https://github.com/getkirby/kirby/commit/2b6fab950bc89d505ea89576bf71c8de614cc3b2 x_refsource_MISC
- https://github.com/getkirby/kirby/commit/e0dca5f709adc21b36f5549df2c0619bc59da56c x_refsource_MISC
- https://github.com/getkirby/kirby/releases/tag/4.9.5 x_refsource_MISC
- https://github.com/getkirby/kirby/releases/tag/5.5.2 x_refsource_MISC