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Vulnerability · Published Sep 7, 2026 · Assigned by VulDB

CVE-2026-86285BookStack Attachment Edit Endpoint AttachmentController.php getUpdateForm access control

Medium 4.3

In plain English

A medium-severity improper access control in BookStack. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).

Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.4%top 67.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
n/a BookStack 26.05.026.05.126.05.2

Weakness: CWE-284, CWE-266 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C

References