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CVE-2026-64649

CVE-2026-64649 · Next.js: Server-Side Request Forgery in Server Actions on Custom Servers

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 8.3 · High · EPSS 0.5% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • next.js

    Versions
    • >= 14.1.1, < 15.5.21: Affected
    • >= 16.0.0 < 16.2.11: Affected

    No fix published

  • next npm

    Affected ranges
    • SEMVER: ≥ 14.1.1, < 15.5.21

    Update to 15.5.21

  • next npm

    Affected ranges
    • SEMVER: ≥ 16.0.0, < 16.2.11

    Update to 16.2.11

Original sources

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