GHSA-wx77-rp39-c6vg
GHSA-wx77-rp39-c6vg is a security vulnerability in markdown. O3 Security confirms whether GHSA-wx77-rp39-c6vg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Regular Expression Denial of Service in markdown
Real-World Exposure
markdownReal-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
All versions of markdown are vulnerable to Regular Expression Denial of Service (ReDoS). The markdown.toHTML() function has significantly degraded performance when parsing long strings containing underscores. This may lead to Denial of Service if the parser accepts user input.
Recommendation
No fix is currently available. Consider using an alternative package until a fix is made available.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | markdown | ≥ 0.0.0 | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for 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.
Remediation status
No patched version of markdown has shipped for GHSA-wx77-rp39-c6vg yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-wx77-rp39-c6vg 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-wx77-rp39-c6vg. 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-wx77-rp39-c6vg in your dependencies?
O3 detects GHSA-wx77-rp39-c6vg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.