CVE-2026-64644: Next Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-q8wf-6r8g-63ch
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CWE-407
Published
Advisory Summary

CVE-2026-64644 is a MODERATE denial of service vulnerability (CWE-407: Inefficient Algorithmic Complexity) affecting Next libraries in the npm ecosystem. The issue involves denial of service in the image optimization api using svgs. Remediation is available by upgrading affected packages to version 15.5.21, 16.2.11.

CVE-2026-64644 at a Glance

CVE Identifier CVE-2026-64644
GHSA Identifier GHSA-q8wf-6r8g-63ch
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-407: Inefficient Algorithmic Complexity
Affected Product Next
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-64644

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-2026-64644, 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-407: Inefficient Algorithmic Complexity, where an algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached. 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 self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in `/_next/image` endpoints. - If you are using `config.images.remotePatterns`, only the patterns in that array are impacted. - If you are using `config.images.unoptimized: true`, you are NOT impacted. - If you are using `config.images.loader: 'custom'`, you are NOT impacted. - If you are using Vercel, you are NOT impacted. ### Workarounds If you cannot upgrade immediately, you can avoid the expensive work by setting `config.experimental.imgOptSkipMetadata : true`.

CVE-2026-64644 Affected Next Versions

2 component(s)
Fixed Versions:
15.5.2116.2.11
Product / Package Ecosystem Affected Versions Fixed Version
next
npm/next
npm
≥ 15.5.0
< 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-q8wf-6r8g-63ch
Next Source Repository REPOSITORY
https://github.com/vercel/next.js/pull/96006
Security Fix Commit FIX COMMIT
https://github.com/vercel/next.js/commit/93cb90891402fa4c47798d03cb9e05c13233766c
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-2026-64644?
CVE-2026-64644 is a security vulnerability in Next involving Denial of Service in the Image Optimization API using SVGs under CWE-407: Inefficient Algorithmic Complexity.
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-2026-64644?
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-2026-64644?
CVE-2026-64644 is classified under CWE-407: Inefficient Algorithmic Complexity (An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.).
How can I check npm dependencies for CVE-2026-64644?
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-q8wf-6r8g-63ch",
  "modified" : "2026-07-22T23:02:05Z",
  "published" : "2026-07-22T23:02:05Z",
  "aliases" : [ "CVE-2026-64644" ],
  "summary" : "Next.js: Denial of Service in the Image Optimization API using SVGs",
  "details" : "### Impact\n\nWhen self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in  `/_next/image` endpoints.\n\n- If you are using `config.images.remotePatterns`, only the patterns in that array are impacted.\n- If you are using `config.images.unoptimized: true`, you are NOT impacted.\n- If you are using `config.images.loader: 'custom'`, you are NOT impacted.\n- If you are using Vercel, you are NOT impacted.\n\n### Workarounds\n\nIf you cannot upgrade immediately, you can avoid the expensive work by setting `config.experimental.imgOptSkipMetadata : true`.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
  } ],
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    },
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      }, {
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  }, {
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  } ],
  "database_specific" : {
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    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-22T23:02:05Z",
    "nvd_published_at" : null
  }
}