CVE-2026-86285CWE-266CWE-284broken-access-control

CVE-2026-86285

Medium · published September 7, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
31.4
In the wild
Unconfirmed
What it is

A vulnerability was detected in BookStack up to 26.05.2. Affected by this issue is the function AttachmentController::getUpdateForm of the file app/Uploads/Controllers/AttachmentController.php of the component Attachment Edit Endpoint. The manipulation of the argument ID results in improper access controls. The attack may be launched remotely. The exploit is now public and may be used. The patch is identified as 4e406c41c4c8060a5795e74c66fb96362e54f400. It is advisable to implement a patch to correct this issue.

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
5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
EPSS
0.00385 · 31.4th percentile
Weaknesses
CWE-266 · Incorrect Privilege Assignment; CWE-284 · Improper Access Control
Published
2026-09-07T13:17Z
References (6)
https://ashutosh-jena.in/blog/broken-access-control-in-bookstack-how-a-missing-permission-check-leaked-attachment-data · [email protected]https://codeberg.org/bookstack/bookstack/commit/4e406c41c4c8060a5795e74c66fb96362e54f400 · [email protected]https://vuldb.com/cve/CVE-2026-86285 · [email protected]https://vuldb.com/submit/905693 · [email protected]https://vuldb.com/vuln/399445 · [email protected]https://vuldb.com/vuln/399445/cti · [email protected]
EPSS history
Timeline
  • 08 SEP 03:24Z
    EPSS moved — → 0%
    epss
  • 07 SEP 08:15Z
    BookStack Attachment Edit Endpoint AttachmentController.php getUpdateForm access control
    cvelistv5