CVE-2026-64643: Next.js is a React framework for building full-stack web applications

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-64643 is a medium-severity flaw (CVSS 5.3) 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 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks co

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 57%)
CISA exploited list	No
Weakness	CWE-201
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 · sugar-calculator · FIXED · 47-14.fc46 · FEDORA-2026-38eeb9e279 · source

sudo dnf upgrade --advisory=FEDORA-2026-38eeb9e279

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

RHEL 10 · firefox · DEFERRED

RHEL 10 · thunderbird · DEFERRED

RHEL 7 · firefox · DEFERRED

RHEL 8 · firefox · DEFERRED

RHEL 8 · thunderbird · DEFERRED

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-2026-64643?

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

Is CVE-2026-64643 being exploited?

CVE-2026-64643 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-2026-64643 affect?

CVE-2026-64643 affects next.js. Severity is medium (CVSS 5.3). 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, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed

How urgent is CVE-2026-64643?

Priority 34/100. Remotely exploitable, no login, no user action

Software pages

React vulnerabilities · Next.js vulnerabilities

Related CVEs

CVE-2026-64641 HIGH 7.5 UPGRADE Next.js is a React framework for building full-stack web applications
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-2026-64646 MEDIUM 5.3 UPGRADE Next.js is a React framework for building full-stack web applications

References

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