CVE-2020-13665 — drupal/core
CRITICALCVE-2020-13665 is a critical-severity (CVSS 9.8) vulnerability in drupal/core. A fix is available for drupal/core — see the affected versions and patch details below.
Drupal Core Access bypass vulnerability
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-13665 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
drupal/core🐘drupal/core🐘drupal/core🐘drupal/drupal🐘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
Access bypass vulnerability in Drupal Core allows JSON:API when JSON:API is in read/write mode. Only sites that have the read_only set to FALSE under jsonapi.settings config are vulnerable. This issue affects: Drupal Drupal Core 8.8.x versions prior to 8.8.8; 8.9.x versions prior to 8.9.1; 9.0.x versions prior to 9.0.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | drupal/core | ≥ 8.8.0&&< 8.8.8 | 8.8.8composer require drupal/core:^8.8.8 |
| 🐘Packagist | drupal/core | ≥ 8.9.0&&< 8.9.1 | 8.9.1composer require drupal/core:^8.9.1 |
| 🐘Packagist | drupal/core | ≥ 9.0.0&&< 9.0.1 | 9.0.1composer require drupal/core:^9.0.1 |
| 🐘Packagist | drupal/drupal | ≥ 8.8.0&&< 8.8.8 | 8.8.8composer require drupal/drupal:^8.8.8 |
| 🐘Packagist | drupal/drupal | ≥ 8.9.0&&< 8.9.1 | 8.9.1composer require drupal/drupal:^8.9.1 |
| 🐘Packagist | drupal/drupal | ≥ 9.0.0&&< 9.0.1 | 9.0.1composer require drupal/drupal:^9.0.1 |
Detection & 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 8.8.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-13665 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2020-13665 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-13665. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-13665 in your dependencies?
O3 Security finds CVE-2020-13665 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.