CVE-2020-15168
MEDIUMCVE-2020-15168 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in node-fetch. O3 Security confirms whether CVE-2020-15168 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
The `size` option isn't honored after following a redirect in node-fetch
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
node-fetchnpmDescription
node-fetch before versions 2.6.1 and 3.0.0-beta.9 did not honor the size option after following a redirect, which means that when a content size was over the limit, a FetchError would never get thrown and the process would end without failure. For most people, this fix will have a little or no impact. However, if you are relying on node-fetch to gate files above a size, the impact could be significant, for example: If you don't double-check the size of the data after fetch() has completed, your JS thread could get tied up doing work on a large file (DoS) and/or cost you money in computing.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | node-fetch | ≥ 2.0.0&&< 2.6.1 | 2.6.1 |
| 📦npm | node-fetch | ≥ 3.0.0-beta.1&&< 3.0.0-beta.9 | 3.0.0-beta.9 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for node-fetch. 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 node-fetch to 2.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15168 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-2020-15168 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-2020-15168. 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-2020-15168 in your dependencies?
O3 detects CVE-2020-15168 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.