CVE-2026-75592
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…
Does this matter?
Lower severity and a low EPSS score (0.46%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.46% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Source
- security-advisories@github.com
References
- https://github.com/getkirby/kirby/commit/2b6fab950bc89d505ea89576bf71c8de614cc3b2
- https://github.com/getkirby/kirby/commit/e0dca5f709adc21b36f5549df2c0619bc59da56c
- https://github.com/getkirby/kirby/releases/tag/4.9.5
- https://github.com/getkirby/kirby/releases/tag/5.5.2
- https://github.com/getkirby/kirby/security/advisories/GHSA-6j4c-mgqr-qv76
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.