CVE-2017-6927 — core
MEDIUMCVE-2017-6927 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in drupal/core. A fix is available for drupal/core — see the affected versions and patch details below.
Drupal cross-site scripting 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
drupal/core🐘drupal/core🐘drupal/drupal🐘drupal/drupalReal-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
Drupal 8.4.x versions before 8.4.5 and Drupal 7.x versions before 7.57 has a Drupal.checkPlain() JavaScript function which is used to escape potentially dangerous text before outputting it to HTML (as JavaScript output does not typically go through Twig autoescaping). This function does not correctly handle all methods of injecting malicious HTML, leading to a cross-site scripting vulnerability under certain circumstances. The PHP functions which Drupal provides for HTML escaping are not affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | drupal/core | ≥ 8.4.0&&< 8.4.5 | 8.4.5composer require drupal/core:^8.4.5 |
| 🐘Packagist | drupal/core | ≥ 7.0&&< 7.57 | 7.57composer require drupal/core:^7.57 |
| 🐘Packagist | drupal/drupal | ≥ 8.4.0&&< 8.4.5 | 8.4.5composer require drupal/drupal:^8.4.5 |
| 🐘Packagist | drupal/drupal | ≥ 7.0&&< 7.57 | 7.57composer require drupal/drupal:^7.57 |
Affected Products
debian linuxdebiandrupaldrupalDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for drupal/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update drupal/core to 8.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-6927 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-2017-6927 in your dependencies?
Find it across Packagist, including transitive dependencies.