GHSA-p6h9-gw49-rqm4 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in markdown2. O3 Security confirms whether GHSA-p6h9-gw49-rqm4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
markdown2 is vulnerable to cross-site scripting
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
GHSA-p6h9-gw49-rqm4 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 0 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
markdown2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in markdown2 (aka python-markdown2) through 2.3.5. The safe_mode feature, which is supposed to sanitize user input against XSS, is flawed and does not escape the input properly. With a crafted payload, XSS can be triggered, as demonstrated by omitting the final > character from an IMG tag.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | markdown2 | all versions | 2.3.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for markdown2. 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 markdown2 to 2.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p6h9-gw49-rqm4 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-p6h9-gw49-rqm4 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-p6h9-gw49-rqm4. 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-p6h9-gw49-rqm4 in your dependencies?
O3 detects GHSA-p6h9-gw49-rqm4 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.