{"id":"CVE-2026-116020","title":"BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages","summary":"BookStack before 26.09.2 contains an incorrect authorization vulnerability in AttachmentController that allows authenticated users to access other users' draft page attachments by ID. Attackers with attachment permissions can enumerate s…","severity":"medium","cvss":5.4,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-863"],"vendor":"BookStackApp","product":"BookStack","affected":["BookStack < 26.09.2"],"published":"2026-10-24","updated":"2026-10-24","sourceUpdated":"2026-10-24T11:40:36.328Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116020","references":[{"url":"https://codeberg.org/bookstack/bookstack/commit/fcadecccda706b4ecaf9ac3f8e27defe0ebe78ae"},{"url":"https://www.bookstackapp.com/blog/bookstack-release-v26-09-2/"},{"url":"https://codeberg.org/bookstack/bookstack/releases/tag/v26.09.2"},{"url":"https://codeberg.org/bookstack/bookstack/src/tag/v26.09.1/app/Uploads/Controllers/AttachmentController.php"},{"url":"https://www.vulncheck.com/advisories/bookstack-before-26.09.2-incorrect-authorization-via-attachmentcontroller-on-draft-pages","label":"VulnCheck Advisory: BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages"}],"tags":["cve.org"],"ingestedAt":"2026-10-24T11:57:47.026Z","slug":"CVE-2026-116020","body":"## Overview\n\nBookStack before 26.09.2 contains an incorrect authorization vulnerability in AttachmentController that allows authenticated users to access other users' draft page attachments by ID. Attackers with attachment permissions can enumerate sequential attachment IDs to download, rename, relink, or replace files on another user's unpublished draft pages.\n\n## Affected\n\n- `BookStack < 26.09.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":29.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}