GHSA-3g8h-86w9-wvmq · Severity: low · Ecosystem: npm — Next.js's Middleware / Proxy redirects can be cache-poisoned
Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, an external client could send a x-nextjs-data header on a normal request to a path handled by middleware that returns a redirect. When that happened, the middleware/proxy could treat the request as a data request and replace the standard Location redirect header with the internal x-nextjs-redirect header. Browsers do not follow x-nextjs-redirect, so the response became an unusable redirect for normal clients. If the application was deployed behind a CDN or reverse proxy that caches 3xx responses without varying on this header, a single attacker request could poison the cached redirect response for the affected path. Subsequent visitors could then receive a cached redirect response without a Location header, causing a denial of service for that redirect path until the cache entry expired or was purged. This vulnerability is fixed in 15.5.16 and 16.2.5.
Conclusion & alert: CVE-2026-44572 is rated Low Risk (14.9/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-14 | — | 0.01% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 3.7 | 3.1 | LOW |
|
2.2 | 1.4 | [email protected] |
| 5.9 | 3.1 | MEDIUM |
|
2.2 | 3.6 | [email protected] |
GHSA-3g8h-86w9-wvmq · Severity: low · Ecosystem: npm — Next.js's Middleware / Proxy redirects can be cache-poisoned
| URL | Tags |
|---|---|
| https://github.com/vercel/next.js/security/advisories/GHSA-3g8h-86w9-wvmq | Mitigation Vendor Advisory |