CVE-2020-13869 — comments
MEDIUMCVE-2020-13869 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in verbb/comments. A fix is available for verbb/comments — see the affected versions and patch details below.
Comments plugin stored Cross-site Scripting via a guest name
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
verbb/commentsReal-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
An issue was discovered in the Comments plugin before 1.5.6 for Craft CMS. There is stored XSS via a guest name.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | verbb/comments | all versions | 1.5.5composer require verbb/comments:^1.5.5 |
Affected Products
commentsverbbDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for verbb/comments, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update verbb/comments to 1.5.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13869 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-2020-13869 in your dependencies?
Find it across Packagist, including transitive dependencies.