CVE-2026-44573: Next.js is a React framework for building full-stack web applications

Q: How do I fix CVE-2026-44573?

next.js: upgrade to 15.5.16, 16.2.5. Exact commands for each OS are on this page.

Q: Is CVE-2026-44573 being exploited?

CVE-2026-44573 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-44573 affect?

CVE-2026-44573 affects next.js. Severity is high (CVSS 7.5). Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access

Q: How urgent is CVE-2026-44573?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-44573 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. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less /_next/data/<buildId>/<page>.json requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JS

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	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-863, CWE-551
Published	2026-05-13
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-13 17:16 UTCPublished CVE record published
2026-10-26 17:10 UTCUpdated Record last modified

vercel next.js UPGRADE

Affected: >= 12.2.0 and < 15.5.16 · >= 16.0.0 and < 16.2.5

Fixed in: 15.5.16, 16.2.5

Safe to downgrade to: a release before 12.2.0

1. Check installed version

npm ls next.js

2. UPGRADE to 15.5.16

npm install next.js@">=15.5.16"

3. If no update is available yet, DOWNGRADE to a release before 12.2.0

npm view next.js versions npm install next.js@"<12.2.0"

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.

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-2026-44573?

next.js: upgrade to 15.5.16, 16.2.5. Exact commands for each OS are on this page.

Is CVE-2026-44573 being exploited?

CVE-2026-44573 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-2026-44573 affect?

CVE-2026-44573 affects next.js. Severity is high (CVSS 7.5). Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access

How urgent is CVE-2026-44573?

Priority 45/100. High severity; Remotely exploitable, no login, no user action

Software pages

React vulnerabilities · Next.js vulnerabilities

Related CVEs

CVE-2026-44572 LOW 3.7 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44575 HIGH 7.5 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44574 HIGH 8.1 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44577 MEDIUM 5.9 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44576 MEDIUM 5.4 UPGRADE Next.js is a React framework for building full-stack web applications

References

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