15.5.21

This release contains security fixes for the following advisories:

High:

• Denial of Service in App Router using Server Actions
• Middleware / Proxy bypass in App Router applications using Turbopack and single locale
• Server-Side Request Forgery in rewrites via attacker-controlled destination hostname
• Server-Side Request Forgery in Server Actions on custom servers

Moderate:

• Cache confusion of response bodies for requests with bodies
• Cache confusion of response bodies for requests with bodies containing invalid UTF-8 byte sequences
• Denial of Service in the Image Optimization API using SVGs
• Unauthenticated disclosure of internal Server Function endpoints
• Unbounded Server Action payload in Edge runtime