CVE-2026-64641: Next.js is a React framework for building full-stack web applications

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-64641 is a high-severity flaw (CVSS 7.5) affecting next.js. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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, crafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process. This issue has been fixed in versions 15.5.21 and 16.2.11.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 42%)
CISA exploited list	No
Weakness	CWE-834
Published	2026-07-27
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: vercel

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-27 18:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

vercel next.js UPGRADE

Affected: >= 13.0.0 and < 15.5.21 · >= 16.0.0 and < 16.2.11

Fixed in: 15.5.21, 16.2.11

Safe to downgrade to: a release before 13.0.0

1. Check installed version

npm ls next.js

2. UPGRADE to 15.5.21

npm install next.js@">=15.5.21"

3. If no update is available yet, DOWNGRADE to a release before 13.0.0

npm view next.js versions npm install next.js@"<13.0.0"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

npm · next · FIXED · 15.5.21 · vulnerable: >= 13.0.0, < 15.5.21 · source

npm install next@">=15.5.21" npm ls next

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

RHEL 10 · firefox · NOT AFFECTED

RHEL 10 · thunderbird · NOT AFFECTED

RHEL 7 · firefox · NOT AFFECTED

RHEL 8 · firefox · NOT AFFECTED

RHEL 8 · thunderbird · NOT AFFECTED

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-64641?

next.js: upgrade to 15.5.21, 16.2.11. Exact commands for each OS are on this page.

Is CVE-2026-64641 being exploited?

CVE-2026-64641 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-64641 affect?

CVE-2026-64641 affects next.js. Severity is high (CVSS 7.5). 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, crafted requests targeting Next.js applications using App Router with at least one Server Action can lead

How urgent is CVE-2026-64641?

Priority 46/100. High severity; Remotely exploitable, no login, no user action

Software pages

React vulnerabilities

Related CVEs

CVE-2026-64642 HIGH 8.2 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-64649 MEDIUM 6.5 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-64644 MEDIUM 5.3 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-64643 MEDIUM 5.3 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-64646 MEDIUM 5.3 UPGRADE Next.js is a React framework for building full-stack web applications

References

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