CVE-2025-49005CWE-444

Next.js cache poisoning due to omission of Vary header

Low · published July 3, 2025

CVSS v3.1
3.7
EPSS
0%
Percentile
41.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
3.7 · LOW
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00491 · 41.2th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2025-07-03T21:01Z
EPSS history
Timeline
  • 03 JUL 21:01Z
    Next.js cache poisoning due to omission of Vary header
    cvelistv5