CVE-2026-64644: next.js — Fix

Description

Next.js is a React framework for building full-stack web applications. In versions 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, 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.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11.

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CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0068

Probability of exploitation

0.49%

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-407 CWE-407

Affected Products

Vendor	Product	Versions
vercel	next.js	15.5.0 — 15.5.21
vercel	next.js	16.0.0 — 16.2.11

References

Advisories & Patches

https://github.com/vercel/next.js/commit/93cb90891402fa4c47798d03cb9e05c13233766c https://github.com/vercel/next.js/pull/96006 https://github.com/vercel/next.js/security/advisories/GHSA-q8wf-6r8g-63ch

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-2026-64644? +

Next.js is a React framework for building full-stack web applications. In versions 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, 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.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-64644? +

CVE-2026-64644 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0068, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-64644? +

CVE-2026-64644 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-2026-64644? +

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.

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