CVE-2026-33490

H3 is a minimal HTTP framework. In versions 2.0.0-0 through 2.0.1-rc.16, the mount method in h3 uses a simple startsWith check to determine whether incoming requests fall under a mounted sub-application's path prefix. Because this check does not verify a path segment boundary i.e., that the next...

GHSA-223J-4RM8-MRMF Next.js may leak x-middleware-subrequest-id to external hosts

Summary In the process of remediating CVE-2025-29927, we looked at other possible exploits of Middleware. We independently verified this low severity vulnerability in parallel with two reports from independent researchers. Learn more here. Credit Thank you to Jinseo Kim kjsman and RyotaK GMO Flat...