4.3Medium
CVE-2026-86285
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.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 4.3 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N- CVSS v4
- 2.1
- Weakness
- CWE-266
- Assigned by
- cna@vuldb.com
Dates
- Published
- 2026-09-07
- Last modified
- 2026-09-09
- Sources
- NVD
References
- https://ashutosh-jena.in/blog/broken-access-control-in-bookstack-how-a-missing-permission-check-leaked-attachment-data
- https://codeberg.org/bookstack/bookstack/commit/4e406c41c4c8060a5795e74c66fb96362e54f400
- https://vuldb.com/cve/CVE-2026-86285
- https://vuldb.com/submit/905693
- https://vuldb.com/vuln/399445
- https://vuldb.com/vuln/399445/cti