CVE-2026-71415
Kirby: File upload permissions are not checked during processing of chunk data
Impact
Kirby is an open-source content management system. From 5.0.0 until 5.5.2, Kirby's REST API chunk upload handler in src/Api/Upload.php did not run the relevant upload authorization preflight in Kirby\Api\Upload::process() before Kirby\Api\Upload::processChunk() persisted chunk data. An authenticated user with the access.panel permission enabled but with files.create, files.replace, and user/users.update permissions disabled could submit requests with an Upload-Length header and leave unfinished chunks in site/cache/.uploads for 24 hours. Repeating this process could consume attacker-controlled temporary storage, prevent other users from uploading files, or prevent site logic from storing data, although final permission checks still prevented unauthorized files from reaching the content or site/accounts directories. This issue is fixed in version 5.5.2.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | getkirby/cms | >= 5.0.0, < 5.5.2 | 5.5.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-67mx-6wf2-92xp
- https://github.com/getkirby/kirby/security/advisories/GHSA-67mx-6wf2-92xp
- https://nvd.nist.gov/vuln/detail/CVE-2026-71415
- https://github.com/getkirby/kirby/pull/8296
- https://github.com/getkirby/kirby/commit/37e206f3ed40ad3fab2e47e055ccb19e9c207dab
- https://github.com/getkirby/kirby/releases/tag/5.5.2