CVE-2024-39126 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in roundup. A fix is available for roundup — see the affected versions and patch details below.
Roundup Cross-site Scripting Vulnerability
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-39126.
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
roundupReal-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
Roundup before 2.4.0 allows XSS via JavaScript in PDF, XML, and SVG documents.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | roundup | all versions | 2.4.0pip install --upgrade 'roundup==2.4.0' |
Affected Products
rounduproundup-trackerDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for roundup, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update roundup to 2.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-39126 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-2024-39126 in your dependencies?
Find it across PyPI, including transitive dependencies.