CVE-2026-45109: Next.js is a React framework for building full-stack web applications

Q: How do I fix CVE-2026-45109?

next.js: upgrade to 15.5.18, 16.2.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-45109 being exploited?

CVE-2026-45109 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-2026-45109 affect?

CVE-2026-45109 affects next.js. Severity is high (CVSS 7.5). Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.18 and 16.2.6, it was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. This vulnerability is fixed

Q: How urgent is CVE-2026-45109?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2026-45109 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 15.2.0 to before 15.5.18 and 16.2.6, it was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. This vulnerability is fixed in 15.5.18 and 16.2.6.

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	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-288, CWE-358
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 18:16 UTCPublished CVE record published
2026-10-26 14:10 UTCUpdated Record last modified

vercel next.js UPGRADE

Affected: >= 15.2.0 and < 15.5.18 · >= 16.0.0 and < 16.2.6

Fixed in: 15.5.18, 16.2.6

Safe to downgrade to: a release before 15.2.0

1. Check installed version

npm ls next.js

2. UPGRADE to 15.5.18

npm install next.js@">=15.5.18"

3. If no update is available yet, DOWNGRADE to a release before 15.2.0

npm view next.js versions npm install next.js@"<15.2.0"

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-2026-45109?

next.js: upgrade to 15.5.18, 16.2.6. Exact commands for each OS are on this page.

Is CVE-2026-45109 being exploited?

CVE-2026-45109 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-2026-45109 affect?

CVE-2026-45109 affects next.js. Severity is high (CVSS 7.5). Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.18 and 16.2.6, it was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. This vulnerability is fixed

How urgent is CVE-2026-45109?

Priority 43/100. High severity; Remotely exploitable, no login, no user action

Software pages

React vulnerabilities · Next.js vulnerabilities

Related CVEs

CVE-2026-44578 HIGH 8.6 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44579 HIGH 7.5 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44580 MEDIUM 6.1 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44582 LOW 3.7 UPGRADE Next.js is a React framework for building full-stack web applications
CVE-2026-44581 MEDIUM 4.7 UPGRADE Next.js is a React framework for building full-stack web applications

References

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