CVE-2026-64642

Published Jul 27, 2026

Last updated a month ago

CVSS high 8.3

Overview

Description
Next.js is a React framework for building full-stack web applications. In versions 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication. This issue has been fixed in version 16.2.11.
Source
security-advisories@github.com
NVD status
Analyzed
Products
next.js

Risk scores

CVSS 4.0

Type
Secondary
Base score
8.3
Impact score
-
Exploitability score
-
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
HIGH

CVSS 3.1

Type
Primary
Base score
8.2
Impact score
4.2
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Severity
HIGH

Weaknesses

security-advisories@github.com
CWE-285

Social media

Hype score
Not currently trending

  1. 一気に9件は、ちょっとフロンティアAI頑張りすぎなのでは。 Next.jsでHigh 4件、Medium 5件が修正された。CVE-2026-64641のServer Actions経由DoS、CVE-2026-64642のMiddleware／Proxy認証回避、CVE-2026-64645とCVE-2026-64649のSSRFを含む。

    @connect24h

    29 Jul 2026

    301 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  2. Next.jsで9件の脆弱性が修正。最も深刻なのはCVE-2026-64645で、CVSSスコア8.3。攻撃者制御下のホストを宛先ホスト名とするrewrites発現。ほか、SSRFのCVE-2026-64649やApp Routerでのプロキシ回避CVE-2026-64642等。 https://t.co/HzZM

    @__kokumoto

    23 Jul 2026

    435 Impressions

    0 Retweets

    2 Likes

    1 Bookmark

    0 Replies

    0 Quotes

  3. Three Next.js vulnerabilities (CVE-2026-64645, CVE-2026-64649, CVE-2026-64642) enable Server-Side Request Forgery and middleware bypass. Patch now. #Nextjs #SSRF #CVE202664645 #WebSecurity #Vercel https://t.co/qMNXEoAOlm

    @Daily_CyberSec

    23 Jul 2026

    375 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

Configurations

Related CVEs

  1. Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.•CVE-2026-64648
  2. 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.•CVE-2026-64649
  3. Next.js is a React framework for building full-stack web applications. In versions 13.0.0 through 15.5.20 and 16.0.0 through 16.2.10, requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive memory consumption if that Server Actions uses the Edge runtime. This issue has been fixed in versions 15.5.21 and 16.2.11.•CVE-2026-64646
  4. Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for 삃삃 and 섄섄 in the request body would share the same cache. This issue has been fixed in versions 15.5.21 and 16.2.11.•CVE-2026-64647
  5. 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.•CVE-2026-64644

References

Sources include official advisories and independent security research.