CVE-2026-64649: next.js SSRF — Fix

Description

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.

Is your site exposed to CVE-2026-64649?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0087

Probability of exploitation

0.56%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-918 Server-Side Request Forgery (SSRF)

Affected Products

Vendor	Product	Versions
vercel	next.js	14.1.1 — 15.5.21
vercel	next.js	16.0.0 — 16.2.11

References

Advisories & Patches

https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498 https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x

Other References

https://github.com/vercel/next.js/releases/tag/v15.5.21 https://github.com/vercel/next.js/releases/tag/v16.2.11

Frequently Asked Questions

What is 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 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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-64649? +

CVE-2026-64649 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0087, placing it in the 1th percentile for exploitation probability.

What products are affected by CVE-2026-64649? +

CVE-2026-64649 affects products from vercel, specifically: next.js. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-64649? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-42336

MaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) …

CVE-2026-41682

pupnp is an SDK for development of UPnP device and control point applications. Prior to version 1.18.5, pupnp is vulnerable …

CVE-2026-44286

FastGPT is an AI Agent building platform. Prior to version 4.14.17, an unauthenticated Server-Side Request Forgery (SSRF) vulnerability allows attackers …

CVE-2026-41172

Squidex is an open source headless content management system and content management hub. Prior to version 7.23.0, an SSRF vulnerability …

CVE-2026-45412

MaxKB is an open-source AI assistant for enterprise. Prior to 2.9.1, SSRF via work_flow_template Import. Authenticated users can supply arbitrary …

CVE-2026-41129

Craft CMS is a content management system (CMS). Versions on the 4.x branch through 4.17.8 and the 5.x branch through …