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.
History

Mon, 31 Aug 2026 22:45:00 +0000

Type Values Removed Values Added
First Time appeared Getkirby
Getkirby kirby
Vendors & Products Getkirby
Getkirby kirby

Mon, 31 Aug 2026 21:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Kirby: File upload permissions are not checked during processing of chunk data
Weaknesses CWE-862
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-31T20:46:02.280Z

Reserved: 2026-08-06T16:28:51.181Z

Link: CVE-2026-71415

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-31T21:17:48.057

Modified: 2026-08-31T21:17:48.057

Link: CVE-2026-71415

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-31T23:15:04Z