CVE-2021-42134 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in django-unicorn. A fix is available for django-unicorn — see the affected versions and patch details below.
Cross-site Scripting in django-unicorn
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
django-unicornReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
The Unicorn framework before 0.36.1 for Django allows XSS via a component. NOTE: this issue exists because of an incomplete fix for CVE-2021-42053.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django-unicorn | all versions | 0.36.1pip install --upgrade 'django-unicorn==0.36.1' |
Affected Products
unicorndjango-unicornDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for django-unicorn, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update django-unicorn to 0.36.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-42134 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-2021-42134 in your dependencies?
Find it across PyPI, including transitive dependencies.