Next.js has a Denial of Service with Server Components
Affected releases · next
- 16.x16.0.0 – 16.2.2Fixed in 16.2.3
- 15.x15.0.0 – 15.5.14Fixed in 15.5.15
- 14.x14.0.0 – 14.2.35No fix on this line yet
- 13.x13.0.0 – 13.5.11No fix on this line yet
On 16.x, the newest line:
npm install next@16.2.3Affected
16.0.0 – 16.2.2
23 releases
Fixed
16.2.3 – 16.4.2
22 releases, latest
Affected
15.0.0 – 15.5.14
69 releases
Fixed
15.5.15 – 15.5.28
13 releases
Affected
14.0.0 – 14.2.35
46 releases
Affected
13.0.0 – 13.5.11
56 releases
Is your project affected?
Paste your package.json, or type the range you declare for next. It is read in your browser and sent nowhere.
What happens
A vulnerability affects certain React Server Components packages for versions 19.x and frameworks that use the affected packages, including Next.js 13.x, 14.x, 15.x, and 16.x using the App Router. The issue is tracked upstream as CVE-2026-23869. You can read more about this advisory our this changelog.
A specially crafted HTTP request can be sent to any App Router Server Function endpoint that, when deserialized, may trigger excessive CPU usage. This can result in denial of service in unpatched environments.