CVE-2020-5256: Remote Code Execution Through Image Uploads in BookStack

high Affects ssddanbrown/bookstack. Feed 2026.10.29.1, updated 2026-10-28; published 2020-03-13; advisory modified 2026-07-08.

Remote Code Execution Through Image Uploads in BookStack

Package: ssddanbrown/bookstack Composer
Affected versions: <0.25.5
Fixed in: 0.25.5
Severity: high CVSS 7.9
Exploitation: not on CISA KEV · EPSS 2% (80.3th percentile)
Published: 2020-03-13
Source: osv.dev

References

CWE-95

NVD record ssddanbrown/bookstack advisories

Am I affected?

Find out in one command. phpwarden checks your composer.lock against this advisory and 20,000+ others, ranked by real-world exploitation (CISA KEV + EPSS). Free, offline, open data.

# one-time install
pip install phpwarden

# then
phpwarden deps composer.lock

Or keep it checked automatically: GitHub Action · pre-commit hook · GitLab CI · Laravel artisan command

Install docs How findings are ranked

Related advisories

CVE-2021-4119 medium BookStack is vulnerable to Improper Access Control. same package: ssddanbrown/bookstack
CVE-2020-26211 high Bookstack Cross-site Scripting vulnerability same package: ssddanbrown/bookstack
CVE-2021-3915 high bookstack is vulnerable to Unrestricted Upload of File with Dangerous Type same package: ssddanbrown/bookstack
CVE-2021-4026 medium bookstack is vulnerable to Improper Access Control same package: ssddanbrown/bookstack
CVE-2020-11055 medium Cross-Site Scripting in BookStack same package: ssddanbrown/bookstack
CVE-2022-0877 medium Cross-site Scripting in BookStack same package: ssddanbrown/bookstack