CVE-2026-64648Next.js: Response Body Cache Confusion for Requests Containing Bodies

Description

Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/vercel/next.js/security/advisories/GHSA-68g3-v927-f742 Vendor Advisory
• https://github.com/vercel/next.js/commit/062f66700b52a5d6bba2c0605d55577ab7ad262c Patch
• https://github.com/vercel/next.js/commit/73b94872bc343d09494b50394d8c08eb9fc8e56a Patch
• https://github.com/vercel/next.js/releases/tag/v15.5.21 ProductRelease Notes
• https://github.com/vercel/next.js/releases/tag/v16.2.11 ProductRelease Notes