PT-2026-83429 · Bookstackapp · Bookstack

CVE-2026-82450

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Published

2026-08-29

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Updated

2026-08-29

CVSS v3.1

8.8

High

VectorAV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
BookStack before 26.05.4 contains a remote code execution vulnerability in the portable ZIP import functionality that allows users with Import Content and Create Books permissions to upload a PHP polyglot file as a book cover. Attackers can bypass image extension validation by embedding a PHP file with a .php filename in the ZIP archive, which is stored in the public web root and executed by unauthenticated requests.

Fix

Unrestricted File Upload

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Weakness Enumeration

Related Identifiers

CVE-2026-82450

Affected Products

Bookstack