CVE-2026-64644: Vercel Next.js

Medium severity, CVSS 5.3. EPSS: 0.7% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. In versions 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, when self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in /_next/image endpoints.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected products

• Vercel Next.js: from 15.5.0, before 15.5.21 (fixed in 15.5.21); from 16.0.0, before 16.2.11 (fixed in 16.2.11)

Published 2026-07-27. Last modified 2026-07-29.