CVE-2024-56510 is a medium-severity (CVSS 5.3) Cross-site Scripting (XSS) vulnerability in @marp-team/marp-core. O3 Security confirms whether CVE-2024-56510 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Marp Core allows XSS by improper neutralization of HTML sanitization
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
@marp-team/marp-corenpmDescription
@marp-team/marp-core is the core for Marp, which is the ecosystem to write your presentation with plain Markdown. Marp Core from v3.0.2 to v3.9.0 and v4.0.0, are vulnerable to cross-site scripting (XSS) due to improper neutralization of HTML sanitization. Marp Core v3.9.1 and v4.0.1 have been patched to fix that. If you are unable to update the package immediately, disable all HTML tags by setting html: false option in the Marp class constructor.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @marp-team/marp-core | ≥ 3.0.2&&< 3.9.1 | 3.9.1 |
| 📦npm | @marp-team/marp-core | ≥ 4.0.0&&< 4.0.1 | 4.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @marp-team/marp-core. 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 @marp-team/marp-core to 3.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-56510 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 CVE-2024-56510 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 CVE-2024-56510. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-56510 in your dependencies?
O3 detects CVE-2024-56510 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.