GHSA-qj3f-9gmq-fwv5
MEDIUMGHSA-qj3f-9gmq-fwv5 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in simple-markdown. O3 Security confirms whether GHSA-qj3f-9gmq-fwv5 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-Site Scripting in simple-markdown
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
simple-markdownnpmDescription
Versions of simple-markdown prior to 0.4.4 are vulnerable to Cross-Site Scripting. Due to insufficient input sanitization the package may render output containing malicious JavaScript. This vulnerability can be exploited through input of links containing data or VBScript URIs and a base64-encoded payload.
Recommendation
Upgrade to version 0.4.4 or later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | simple-markdown | all versions | 0.4.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for simple-markdown. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update simple-markdown to 0.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qj3f-9gmq-fwv5 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.
How O3 protects you
O3 pinpoints whether GHSA-qj3f-9gmq-fwv5 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-qj3f-9gmq-fwv5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-qj3f-9gmq-fwv5 in your dependencies?
O3 detects GHSA-qj3f-9gmq-fwv5 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.