CVE-2018-20418 — cms
MEDIUMCVE-2018-20418 is a medium-severity (CVSS 4.8) Cross-site Scripting (XSS) vulnerability in craftcms/cms. 4 public exploit or proof-of-concept references are indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Craft CMS Cross-site Scripting (XSS) Vulnerability
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
craftcms/cmsReal-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
index.php?p=admin/actions/entries/save-entry in Craft CMS 3.0.25 allows XSS by saving a new title from the console tab.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | all versions | No fix |
Affected Products
craft cmscraftcmsResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Craft CMS 3.0.25 - Cross-Site Scripting
by Raif Berkay Dincel · Dec 27, 2018
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of craftcms/cms for CVE-2018-20418. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
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-2018-20418 in your dependencies?
Find it across Packagist, including transitive dependencies.