CVE-2021-36440: Unrestricted File Upload in ShowDoc v2.9.5

critical Affects showdoc/showdoc. Feed 2026.10.29.1, updated 2026-10-28; published 2021-09-09; advisory modified 2023-11-08.

Unrestricted File Upload in ShowDoc v2.9.5

Package: showdoc/showdoc Composer
Affected versions: <2.9.6
Fixed in: 2.9.6
Severity: critical CVSS 9.8
Exploitation: not on CISA KEV · EPSS 5% (91.9th percentile)
Published: 2021-09-09
Source: osv.dev

References

CWE-434

NVD record showdoc/showdoc 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-2022-0967 medium Stored Cross-site Scripting in showdoc same package: showdoc/showdoc
CVE-2025-0520 critical ShowDoc unrestricted file upload vulnerability same package: showdoc/showdoc
CVE-2022-1034 high Unrestricted Upload of File with Dangerous Type in ShowDoc same package: showdoc/showdoc
CVE-2022-0362 medium SQL Injection in showdoc same package: showdoc/showdoc
CVE-2021-41745 critical Showdoc File Upload Vulnerability same package: showdoc/showdoc
CVE-2018-19620 medium Showdoc Unauthenticated Access same package: showdoc/showdoc