CVE-2025-24981
📋 TL;DR
CVE-2025-24981 is a cross-site scripting (XSS) vulnerability in the MDC markdown parser that allows attackers to bypass URL filtering by encoding JavaScript URLs with hex HTML entities. This enables arbitrary JavaScript execution when users click malicious links in parsed markdown content. All applications using vulnerable versions of MDC that process untrusted markdown input are affected.
💻 Affected Systems
- MDC (Markdown Components) for Vue/Nuxt
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, session hijacking, or malware distribution through client-side attacks when users interact with malicious markdown content.
Likely Case
Stored XSS attacks leading to credential theft, data exfiltration, or unauthorized actions in user sessions.
If Mitigated
Limited impact with proper input validation and output encoding, though the vulnerability bypasses existing security controls.
🎯 Exploit Status
The exploit requires user interaction (clicking a link) but the bypass technique is simple and well-documented in the advisory.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.13.3
Vendor Advisory: https://github.com/nuxt-modules/mdc/security/advisories/GHSA-j82m-pc2v-2484
Restart Required: No
Instructions:
1. Update MDC dependency to version 0.13.3 or later. 2. Run npm update @nuxtjs/mdc or yarn upgrade @nuxtjs/mdc. 3. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Input sanitization
allImplement additional URL validation and sanitization before passing markdown to MDC parser
🧯 If You Can't Patch
- Disable markdown parsing from untrusted sources entirely
- Implement strict Content Security Policy (CSP) to block inline JavaScript execution
🔍 How to Verify
Check if Vulnerable:
Check package.json for MDC version below 0.13.3 and verify if your application processes user-provided markdownCheck Version:
npm list @nuxtjs/mdc or check package.json for "@nuxtjs/mdc" versionVerify Fix Applied:
Confirm MDC version is 0.13.3 or higher in package.json and test with known malicious payloads📡 Detection & Monitoring
Log Indicators:
- Unusual markdown parsing errors
- JavaScript execution from markdown links
- URLs with hex-encoded javascript: protocol
Network Indicators:
- Outbound connections triggered by markdown content
- Suspicious JavaScript payloads in markdown processing
SIEM Query:
Search for 'javascript:' variations in user input or markdown processing logs, particularly hex-encoded versions