CVE-2026-82450: BookStack before 26.05.4 Remote Code Execution via Book Cover
bookstackapp · bookstack
Fixed in 26.05.4 · Affected: bookstackapp before 26.05.4 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 63% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- bookstackapp · bookstackbefore 26.05.4
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- bookstackapp
- Published
- August 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-82450 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.