CVE-2025-59717
MEDIUMCVE-2025-59717 is a medium-severity (CVSS 5.4) CWE-843 vulnerability in @digitalocean/do-markdownit. O3 Security confirms whether CVE-2025-59717 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
@digitalocean/do-markdownit has Type Confusion vulnerability
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.
@digitalocean/do-markdownitnpmDescription
In the @digitalocean/do-markdownit package through 1.16.1 (in npm), the callout and fence_environment plugins perform .includes substring matching if allowedClasses or allowedEnvironments is a string (instead of an array).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @digitalocean/do-markdownit | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @digitalocean/do-markdownit. 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 @digitalocean/do-markdownit has shipped for CVE-2025-59717 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 CVE-2025-59717 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-2025-59717. 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-2025-59717 in your dependencies?
O3 detects CVE-2025-59717 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.