CVE-2025-49826
High
Description
Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact customers hosted on Vercel. Under certain conditions, this issue may allow a HTTP 204 response to be cached for static pages, leading to the 204 response being served to all users attempting to access the page. This issue has been addressed in version 15.1.8.
SeverityHigh
CVSS7.5
Exploit probability67. percentile1.1%
Product
Vercel Next.js
PublishedJul 3, 2025
First seenJul 3, 2025
Weakness typeCWE-444CWE-444
How to fix
Update
- vercel next.js15.1.8 or later
- next15.1.8 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| vercel next.js | 15.0.4 < v < 15.1.8, 15.0.4 | 15.1.8 |
| nextnpm | 15.0.4-canary.51 ≤ v < 15.1.8 | 15.1.8 |
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