Vulnerability in Vercel Next.js
CVE-2026-44576
Next.js is a React framework for building full-stack web applications. From 14.2.0 to before 15.5.16 and 16.2.5, applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML. This vulnerability is fixed in 15.5.16 and 16.2.5.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (21.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 22nd percentile — 21.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Vercel Next.js — versions >= 14.2.0, < 15.5.16, >= 16.0.0, < 16.2.5
Weakness classification (CWE)
References
- github.com/vercel/next.js/security/advisories/GHSA-wfc6-r584-vfw7 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-44576?
- CVE-2026-44576 is a medium-severity vulnerability in Vercel Next.js, classified under CWE-436. CVSS score: 5.4/10. Published 2026-05-13.
- How severe is CVE-2026-44576?
- Medium severity. CVSS v3 base score is 5.4 out of 10.