CVE-2026-14620
MEDIUMwebpack-dev-server vulnerable to cross-site request forgery via internal developer endpoints
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
webpack-dev-servernpmDescription
webpack-dev-server versions 5.2.5 and earlier expose two internal developer endpoints, /webpack-dev-server/open-editor and /webpack-dev-server/invalidate, that perform state-changing actions on any GET request without verifying that the request originated from the dev server's own page. Any website a developer visits while the dev server is running can trigger these endpoints cross-origin with no interaction beyond the visit. An attacker can open an arbitrary existing local file in the developer's editor, including files outside the project root, and repeated requests can spawn editor processes and force recompilations that degrade the developer's machine. Patches: upgrade to webpack-dev-server 5.2.6. Workarounds: none.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | webpack-dev-server | all versions | 5.2.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for webpack-dev-server. 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 webpack-dev-server to 5.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-14620 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-2026-14620 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-2026-14620. 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-2026-14620 in your dependencies?
O3 detects CVE-2026-14620 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.