CVE-2026-28736

Name: CVE-2026-28736
Creator: NVD / NIST
Published: 2026-04-03T14:16:29.517+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2026-28736 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. ** 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.22%

12.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-639

Affected Software

Vendor	Product	Versions
Mattermost	Focalboard	8.0.0

References

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

Timeline

Published: Apr 3, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-28736?

How severe is CVE-2026-28736?

CVE-2026-28736 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-28736?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-28736?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST