CVE-2026-28736CWE-639

CVE-2026-28736

Medium · published April 3, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
18.2
In the wild
Unconfirmed
What it is

** 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.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00270 · 18.2th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-04-03T18:16Z
Affected products (1)
ProductVersionsFixed in
mattermost/focalboardall versions—
References (1)
https://github.com/mattermost-community/focalboard · [email protected]
EPSS history
Timeline
  • 03 APR 13:25Z
    Focalboard IDOR in file content endpoint allows cross-user file access (unsupported product, no fix)
    cvelistv5