GHSA-45c6-75p6-83cc
MEDIUMGHSA-45c6-75p6-83cc is a medium-severity (CVSS 6.1) vulnerability in fast-xml-builder. O3 Security confirms whether GHSA-45c6-75p6-83cc is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
fast-xml-builder Comment Value regex can be bypassed
Blast Radius
fast-xml-builderReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The fix for https://github.com/advisories/GHSA-gh4j-gqv2-49f6 in fast-xml-parser sanitizes -- sequences in XML comment content using .replace(/--/g, '- -'). This skip the values containing three consecutive dashes (e.g., --->...), allowing an attacker to break out of an XML comment and inject arbitrary XML/HTML content.
Impact
Any application with comment property enabled allow attacker to inject malicious or unwanted code like JS script tag in the XML/HTML output.
Workarounds
Check for the presence of 3 consecutive dashes externally in the property value used for comment tag.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | fast-xml-builder | ≥ 1.1.5&&< 1.1.6 | 1.1.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fast-xml-builder. 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 fast-xml-builder to 1.1.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-45c6-75p6-83cc 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-45c6-75p6-83cc 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-45c6-75p6-83cc. 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-45c6-75p6-83cc in your dependencies?
O3 detects GHSA-45c6-75p6-83cc across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.