CVE-2026-28736

** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files. This allows an authenticated attacker who knows a victim's fileID to read the content of the file. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/mattermost-community/focalboard	Product

Configurations

Configuration 1 (hide)

cpe:2.3:a:mattermost:focalboard:8.0.0:*:*:*:*:*:*:*

History

24 Jul 2026, 21:10

Type	Values Removed	Values Added
Summary		(es) NO COMPATIBLE CUANDO ASIGNADO La versión 8.0 de Focalboard no valida la propiedad de los archivos al servir archivos subidos. Esto permite a un atacante autenticado que conoce el ID de archivo de una víctima leer el contenido del archivo. NOTA: Focalboard como producto independiente no recibe mantenimiento y no se emitirá ninguna corrección.

28 Apr 2026, 00:19

Type	Values Removed	Values Added
First Time		Mattermost Mattermost focalboard
CPE		cpe:2.3:a:mattermost:focalboard:8.0.0:::::::*
References	~~() https://github.com/mattermost-community/focalboard -~~	() https://github.com/mattermost-community/focalboard - Product

03 Apr 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-03 14:16

Updated : 2026-07-24 21:10

NVD link : CVE-2026-28736

Mitre link : CVE-2026-28736

CVE.ORG link : CVE-2026-28736

JSON object : View

Products Affected

mattermost

focalboard

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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