SEPTEMBER 18, 2026
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Case File

CVE-2026-82450

HIGH · CVSS 8.8 EPSS 0.57% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-29 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability affects BookStack versions prior to 26.05.4, allowing users with Import Content and Create Books permissions to exploit the portable ZIP import feature. By uploading a specially crafted ZIP file containing a PHP polyglot file as a book cover, attackers can bypass image extension validation, leading to remote code execution on the server. Organizations using BookStack should prioritize patching this vulnerability to prevent unauthorized access and potential compromise of their systems.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
remote code execution code execution

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-82450
Severity
HIGH
CVSS
8.8
EPSS
0.57%

Original NVD 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.