GHSA-r2fc-ccr8-96c4

Next.js has a Cache poisoning vulnerability due to omission of the Vary header

Source: GitHub Advisory Database (reviewed) Low CVE-2025-49005

Packages

Ecosystem	Package	Affected	Fixed in
npm	next	>= 15.3.0, < 15.3.3	15.3.3

Details

As written in the advisory (Markdown source, shown as plain text).

### Summary A cache poisoning issue in **Next.js App Router >=15.3.0 and < 15.3.3** may have allowed RSC payloads to be cached and served in place of HTML, under specific conditions involving middleware and redirects. This issue has been fixed in **Next.js 15.3.3**. Users on affected versions should **upgrade immediately** and **redeploy** to ensure proper caching behavior. More details: [CVE-2025-49005](https://vercel.com/changelog/cve-2025-49005)

References

External links from the advisory. They lead to third-party sites.

https://github.com/vercel/next.js/security/advisories/GHSA-r2fc-ccr8-96c4 web
https://nvd.nist.gov/vuln/detail/CVE-2025-49005 advisory
https://github.com/vercel/next.js/issues/79346 web
https://github.com/vercel/next.js/pull/79939 web
https://github.com/vercel/next.js/commit/ec202eccf05820b60c6126d6411fe16766ecc066 web
https://github.com/vercel/next.js package
https://github.com/vercel/next.js/releases/tag/v15.3.3 web
https://vercel.com/changelog/cve-2025-49005 web