VULNERABILITY INTELLIGENCE
CVE-2026-82450
CVSS score8.8 HIGH
EPSS probability1.00%
CISA KEVNot currently listed
Published2026-08-29
Last modified2026-10-08
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
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.
Weakness classification
- disclosure@vulncheck.com: CWE-434