CVE-2026-28736 — MEDIUM (4.3)

Vulnerability Description

** 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 Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

NONE

Availability

NONE

Affected Products

Vendor	Product	Versions
Mattermost	Focalboard	8.0.0

Related Weaknesses (CWE)

CWE-639

References

https://github.com/mattermost-community/focalboardProduct

FAQ

What is CVE-2026-28736?

CVE-2026-28736 is a vulnerability with a CVSS score of 4.3 (MEDIUM). ** 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 conte...

How severe is CVE-2026-28736?

CVE-2026-28736 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-28736?

Check the references section above for vendor advisories and patch information. Affected products include: Mattermost Focalboard.