TI-2026-50044 Aliases CVE-2026-71415 GHSA-67mx-6wf2-92xp

Kirby: File upload permissions are not checked during processing of chunk data

LOW 32CWE-862Published 2026-08-31 · Updated 2026-09-03

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Security bypass
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-862.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00427 37th percentileScored 2026-11-07

Fix Fixed kirby (getkirby): 5.5.2getkirby/cms (Packagist): 5.5.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
getkirby	kirby	5.0.0 to before 5.5.2	5.5.2	Patch available	CNA
—	getkirby/cms (Packagist)	5.0.0 to before 5.5.2	5.5.2	Patch available	GHSA-67mx-6wf2-92xp

kirby Vendorgetkirby Affected 5.0.0 to before 5.5.2 Fixed in 5.5.2 Patch available CNA
getkirby/cms (Packagist) Vendor— Affected 5.0.0 to before 5.5.2 Fixed in 5.5.2 Patch available GHSA-67mx-6wf2-92xp

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:getkirby:kirby::::::::	—	—	getkirby

cpe:2.3:a:getkirby:kirby:*:*:*:*:*:*:*:* Versions — — ·getkirby

Remediation

Fix · CNA kirby (getkirby) Fixed in 5.5.2
Fix · GHSA-67mx-6wf2-92xp getkirby/cms (Packagist) Fixed in 5.5.2 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-71415
2026-10-03 Alias added: GHSA-67mx-6wf2-92xp

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-71415

Other 5

TI-2024-17440 An arbitrary file upload vulnerability in the Profile Image module of Kirby CMS v4.1.0… CVSS 3.1HIGH 8.8
TI-2024-17439 An HTML injection vulnerability exists in the Edit Content Layout module of Kirby CMS… CVSS 3.1HIGH 7.1
TI-2026-23396 Kirby CMS through 5.1.4 allows an authenticated user with 'Editor' permissions to cause a… CVSS 3.1MEDIUM 6.5
TI-2024-17441 A stored cross-site scripting (XSS) vulnerability in the Edit Content Layout module of… CVSS 3.1MEDIUM 6.1
TI-2018-10413 An issue was discovered in Kirby 2.5.12. CVSS 3.1MEDIUM 5.4
TI-2024-17438 Kirby CMS v4.1.0 was discovered to contain a reflected self-XSS vulnerability via the URL parameter. CVSS 3.1MEDIUM 4.7

See all 61 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences