CVE-2025-31138 is a medium-severity (CVSS 5.5) CWE-1021 vulnerability in tarteaucitronjs. A fix is available for tarteaucitronjs — see the affected versions and patch details below.
tarteaucitron.js allows UI manipulation via unrestricted CSS injection
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2025-31138.
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
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
tarteaucitronjsnpmDescription
A vulnerability was identified in tarteaucitron.js, where user-controlled inputs for element dimensions (width and height) were not properly validated. This allowed an attacker with direct access to the site's source code or a CMS plugin to set values like 100%;height:100%;position:fixed;, potentially covering the entire viewport and facilitating clickjacking attacks.
Impact
An attacker with high privileges could exploit this vulnerability to:
- Overlay malicious UI elements on top of legitimate content,
- Trick users into interacting with hidden elements (clickjacking),
- Disrupt the intended functionality and accessibility of the website.
Fix https://github.com/AmauriC/tarteaucitron.js/commit/25fcf828aaa55306ddc09cfbac9a6f8f126e2d07
The issue was resolved by enforcing strict validation and sanitization of user-provided CSS values to prevent unintended UI manipulation.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | tarteaucitronjs | all versions | 1.20.1npm install tarteaucitronjs@1.20.1 |
Affected Products
tarteaucitronjsamauriDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tarteaucitronjs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tarteaucitronjs to 1.20.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-31138 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.
Frequently Asked Questions
Is CVE-2025-31138 in your dependencies?
Find it across npm, including transitive dependencies.