CVE-2026-25957
MEDIUMCVE-2026-25957 is a medium-severity (CVSS 6.5) CWE-755 vulnerability in @cubejs-backend/server-core. O3 Security confirms whether CVE-2026-25957 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cube Denial of Service (DoS) - An authenticated attacker can crash the server by sending a specially crafted request
Real-World Exposure
@cubejs-backend/server-core📦@cubejs-backend/server-coreReal-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
Cube is a semantic layer for building data applications. From 1.1.17 to before 1.5.13 and 1.4.2, it is possible to make the entire Cube API unavailable by submitting a specially crafted request to a Cube API endpoint. This vulnerability is fixed in 1.5.13 and 1.4.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @cubejs-backend/server-core | ≥ 1.1.17&&< 1.4.2 | 1.4.2 |
| 📦npm | @cubejs-backend/server-core | ≥ 1.5.0&&< 1.5.13 | 1.5.13 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @cubejs-backend/server-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 @cubejs-backend/server-core to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25957 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-2026-25957 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-2026-25957. 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-2026-25957 in your dependencies?
O3 detects CVE-2026-25957 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.