Vulnerability · Published Jul 3, 2025 · Assigned by GitHub_M
CVE-2025-49005Next.js cache poisoning due to omission of Vary header
Low 3.7
In plain English
A low-severity security flaw in next.js from vercel. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Next.js is a React framework for building full-stack web applications. In Next.js App Router from 15.3.0 to before 15.3.3 and Vercel CLI from 41.4.1 to 42.2.0, a cache poisoning vulnerability was found. The issue allowed page requests for HTML content to return a React Server Component (RSC) payload instead under certain conditions. When deployed to Vercel, this would only impact the browser cache, and would not lead to the CDN being poisoned. When self-hosted and deployed externally, this could lead to cache poisoning if the CDN does not properly distinguish between RSC / HTML in the cache keys. This issue has been resolved in Next.js 15.3.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | next | 15.3.3 | GHSA-r2fc-ccr8-96c4 |
Affected products (as reported)
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://github.com/vercel/next.js/security/advisories/GHSA-r2fc-ccr8-96c4 x_refsource_CONFIRM
- https://github.com/vercel/next.js/issues/79346 x_refsource_MISC
- https://github.com/vercel/next.js/commit/ec202eccf05820b60c6126d6411fe16766ecc066 x_refsource_MISC
- https://github.com/vercel/next.js/releases/tag/v15.3.3 x_refsource_MISC
- https://vercel.com/changelog/cve-2025-49005 x_refsource_MISC