CVE-2026-29057: Next.js: HTTP request smuggling in rewrites
(updated )
When Next.js rewrites proxy traffic to an external backend, a crafted DELETE/OPTIONS request using Transfer-Encoding: chunked could trigger request boundary disagreement between the proxy and backend. This could allow request smuggling through rewritten routes.
References
- github.com/advisories/GHSA-ggv3-7p47-pfv8
- github.com/vercel/next.js
- github.com/vercel/next.js/commit/dc98c04f376c6a1df76ec3e0a2d07edf4abdabd6
- github.com/vercel/next.js/releases/tag/v15.5.13
- github.com/vercel/next.js/releases/tag/v16.1.7
- github.com/vercel/next.js/security/advisories/GHSA-ggv3-7p47-pfv8
- nvd.nist.gov/vuln/detail/CVE-2026-29057
Code Behaviors & Features
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