CVE-2020-23263 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in forkcms/forkcms. A fix is available for forkcms/forkcms — see the affected versions and patch details below.
Cross-site scripting in forkcms
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-23263 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
forkcms/forkcmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Persistent Cross-site scripting vulnerability on Fork CMS version 5.8.2 allows remote attackers to inject arbitrary Javascript code via the "navigation_title" parameter and the "title" parameter in /private/en/pages/add.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | forkcms/forkcms | all versions | 5.8.3composer require forkcms/forkcms:^5.8.3 |
Affected Products
fork cmsfork-cmsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for forkcms/forkcms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update forkcms/forkcms to 5.8.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-23263 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2020-23263 in your dependencies?
Find it across Packagist, including transitive dependencies.