CVE-2026-64649: Next Server-Side Request Forgery Vulnerability

HIGH
Advisory Identifier: GHSA-89xv-2m56-2m9x
Share
CWE-918
Published
Advisory Summary

CVE-2026-64649 is a HIGH server-side request forgery vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Next libraries in the npm ecosystem. The issue involves server-side request forgery in server actions on custom servers. Remediation is available by upgrading affected packages to version 15.5.21, 16.2.11.

CVE-2026-64649 at a Glance

CVE Identifier CVE-2026-64649
GHSA Identifier GHSA-89xv-2m56-2m9x
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product Next
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-64649

To remediate this vulnerability, upgrade all affected Next dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

next fixed: 15.5.21 
npm install next@15.5.21
next fixed: 16.2.11 
npm install next@16.2.11
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls next

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-64649, inspect your project dependencies using npm:

npm ls next

Analyze the terminal output to locate any version of Next in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 15.5.21), your application is affected.

Note: The npm ls next command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. In Next, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact 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. ## Workarounds If you cannot upgrade, ensure clients do not control the host header your application receives. Pin or validate `Host` and `X-Forwarded-Host` at your edge or proxy. On version 14.2.0 and later, you can additionally set the `__NEXT_PRIVATE_ORIGIN` environment variable to your deployment's real origin: ```bash __NEXT_PRIVATE_ORIGIN=https://www.example.com node server.js

CVE-2026-64649 Affected Next Versions

2 component(s)
Fixed Versions:
15.5.2116.2.11
Product / Package Ecosystem Affected Versions Fixed Version
next
npm/next
npm
≥ 14.1.1
< 15.5.21
15.5.21
next
npm/next
npm
≥ 16.0.0
< 16.2.11
16.2.11

References

GitHub Advisory / Wiki ADVISORY
https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x
Security Fix Commit FIX COMMIT
https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b
Security Fix Commit FIX COMMIT
https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498
Next Source Repository REPOSITORY
https://github.com/vercel/next.js
Next Release RELEASE
https://github.com/vercel/next.js/releases/tag/v15.5.21
Next Release RELEASE
https://github.com/vercel/next.js/releases/tag/v16.2.11

Frequently Asked Questions

What is CVE-2026-64649?
CVE-2026-64649 is a security vulnerability in Next involving Server-Side Request Forgery in Server Actions on custom servers under CWE-918: Server-Side Request Forgery (SSRF).
Which Next versions are affected?
Affected versions include releases prior to 15.5.21, 16.2.11 across affected packages: next.
What version fixes CVE-2026-64649?
Upgrading to 15.5.21, 16.2.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is next affected?
Yes, next is affected in releases prior to 15.5.21, 16.2.11. Upgrade your dependency to 15.5.21, 16.2.11 or later.
What CWE is associated with CVE-2026-64649?
CVE-2026-64649 is classified under CWE-918: Server-Side Request Forgery (SSRF) (The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.).
How can I check npm dependencies for CVE-2026-64649?
Run the dependency tree command: 'npm ls next'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-89xv-2m56-2m9x",
  "modified" : "2026-07-22T23:09:48Z",
  "published" : "2026-07-22T23:09:48Z",
  "aliases" : [ "CVE-2026-64649" ],
  "summary" : "Next.js: Server-Side Request Forgery in Server Actions on custom servers",
  "details" : "## Impact\n\nWhen 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.\n\nApplications 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.\n\n## Workarounds\n\nIf you cannot upgrade, ensure clients do not control the host header your application receives. Pin or validate `Host` and `X-Forwarded-Host` at your edge or proxy. On version 14.2.0 and later, you can additionally set the `__NEXT_PRIVATE_ORIGIN` environment variable to your deployment's real origin:\n\n```bash\n__NEXT_PRIVATE_ORIGIN=https://www.example.com node server.js",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "next"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "14.1.1"
      }, {
        "fixed" : "15.5.21"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "next"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "16.0.0"
      }, {
        "fixed" : "16.2.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/vercel/next.js"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vercel/next.js/releases/tag/v15.5.21"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/vercel/next.js/releases/tag/v16.2.11"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-22T23:09:48Z",
    "nvd_published_at" : null
  }
}