CVE-2025-21610 is a medium-severity (CVSS 5.3) Cross-site Scripting (XSS) vulnerability in trix. A fix is available for trix — see the affected versions and patch details below.
Trix allows Cross-site Scripting via `javascript:` url in a link
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-2025-21610.
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-2025-21610 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 379,145 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
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.
trixnpmDescription
The Trix editor, versions prior to 2.1.11, is vulnerable to XSS when pasting malicious code in the link field.
Impact
An attacker could trick the user to copy&paste a malicious javascript: URL as a link that would execute arbitrary JavaScript code within the context of the user's session, potentially leading to unauthorized actions being performed or sensitive information being disclosed.
See https://gist.github.com/th4s1s/3921fd9c3e324ad9a3e0d846166e3eb8
Patches
Update Recommendation: Users should upgrade to Trix editor version 2.1.12 or later.
Workarounds
This is not really a workaround but something that should be considered in addition to upgrading to the patched version. If affected users can disallow browsers that don't support a Content Security Policy, then this would be an effective workaround for this and all XSS vulnerabilities. Set CSP policies such as script-src 'self' to ensure that only scripts hosted on the same origin are executed, and explicitly prohibit inline scripts using script-src-elem.
References
https://gist.github.com/th4s1s/3921fd9c3e324ad9a3e0d846166e3eb8
Credits
This vulnerability was reported by Hackerone researcher https://hackerone.com/lio346?type=user
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | trix | all versions | 2.1.12npm install trix@2.1.12 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for trix, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update trix to 2.1.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-21610 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-21610 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-21610. 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-2025-21610 in your dependencies?
O3 Security finds CVE-2025-21610 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.