CVE-2025-32421
LOWCVE-2025-32421 is a low-severity (CVSS 3.7) CWE-362 vulnerability in next. O3 Security confirms whether CVE-2025-32421 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Next.js Race Condition to Cache Poisoning
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.
nextnpmDescription
Next.js is a React framework for building full-stack web applications. Versions prior to 14.2.24 and 15.1.6 have a race-condition vulnerability. This issue only affects the Pages Router under certain misconfigurations, causing normal endpoints to serve pageProps data instead of standard HTML. This issue was patched in versions 15.1.6 and 14.2.24 by stripping the x-now-route-matches header from incoming requests. Applications hosted on Vercel's platform are not affected by this issue, as the platform does not cache responses based solely on 200 OK status without explicit cache-control headers. Those who self-host Next.js deployments and are unable to upgrade immediately can mitigate this vulnerability by stripping the x-now-route-matches header from all incoming requests at the content development network and setting cache-control: no-store for all responses under risk. The maintainers of Next.js strongly recommend only caching responses with explicit cache-control headers.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | next | ≥ 0.9.9&&< 14.2.24 | 14.2.24 |
| 📦npm | next | ≥ 15.0.0&&< 15.1.6 | 15.1.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for next. 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 next to 14.2.24 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-32421 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-2025-32421 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-2025-32421. 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-2025-32421 in your dependencies?
O3 detects CVE-2025-32421 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.