CVE-2026-53945
MEDIUMCVE-2026-53945 is a medium-severity (CVSS 4) CWE-367 vulnerability in ghost. O3 Security confirms whether CVE-2026-53945 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Ghost: Server-side request forgery via DNS rebinding in external request handling
Blast Radius
ghostReal-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
Ghost is a Node.js content management system. From 6.0.9 until 6.21.1, Ghost’s private-IP check for outbound HTTP requests could be bypassed via DNS rebinding, allowing an attacker to coerce the Ghost server into reaching hosts on internal networks through features that issue external fetches. This vulnerability is fixed in 6.21.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ghost | ≥ 6.0.9&&< 6.21.2 | 6.21.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ghost. 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 ghost to 6.21.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53945 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-2026-53945 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-2026-53945. 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-2026-53945 in your dependencies?
O3 detects CVE-2026-53945 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.