CVE-2026-64649: Next.js is a React framework for building full-stack web applications. In versions 14.1.1 through 15.5.20 and 16.0.0 through 16.2.10, when a Server Action forwards or redirects a r

mediumCVSS 6.5CVE-2026-64649

Next.js is a React framework for building full-stack web applications. In versions 14.1.1 through 15.5.20 and 16.0.0 through 16.2.10, when a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker's request to control Host-associated headers. In some configurations, it's also possible to obtain internal values that weaken middleware/proxy authorization. Applications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; next start and standalone output do the same from version 14.2 onward. This issue has been fixed in versions 15.5.21 and 16.2.11.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 6.5
Published: 2026-07-27
Last updated: 2026-07-29
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-64649

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-646490.45% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64649	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for Next.js is a

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEW] [high] Vercel Next.js: Multiple Vulnerabilitiescert-bund · 2026-07-28
mediumCVE-2026-64648: Next.js is a React framework for building full-stack web applications. In versions 12.0.0 thro…nvd · 2026-07-27
mediumCVE-2026-64647: Next.js is a React framework for building full-stack web applications. In versions 12.0.0 thro…nvd · 2026-07-27
mediumCVE-2026-64646: Next.js is a React framework for building full-stack web applications. In versions 13.0.0 thro…nvd · 2026-07-27
mediumCVE-2026-64645: Next.js is a React framework for building full-stack web applications. In versions 12.0.0 thro…nvd · 2026-07-27
mediumCVE-2026-64644: Next.js is a React framework for building full-stack web applications. In versions 15.5.0 thro…nvd · 2026-07-27