BookStack before 26.05.4 Remote Code Execution via Book Cover
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.
CVE-2026-82450
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-82450
bookstack
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "bookstackapp",
"product": "bookstack",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "26.05.4",
"versionType": "custom"
}
],
"packageURL": "pkg:composer/ssddanbrown/bookstack",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-82450
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #13003 · Revision 1
- Added to Heist Feed
- Publisher date