CVE-2026-45109: Next.js: Middleware / Proxy bypass in App Router applications via segment-prefetch routes

Published May 11, 2026
·
Updated

### Impact It was found that the fix addressing [CVE-2026-44575](https://github.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f) did not apply to `middleware.ts` with Turbopack. Refer to [CVE-2026-44575](https://github.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f) for further details. ### References - [CVE CVE-2026-44575](https://github.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f)

Affected Software

4 affected componentsFixes available
npm/next>=16.0.0<16.2.6
16.2.6
npm/next>=15.2.0<15.5.18
15.5.18
Vercel Next.js Node.js>=15.2.0<15.5.18
Vercel Next.js Node.js>=16.0.0<16.2.6

Event History

May 11, 2026
Advisory Published
via GitHub·04:21 PM
Data Sourced
via GitHub·04:21 PM
DescriptionSeverityWeaknessAffected Software
May 13, 2026
CVE Published
via MITRE·05:11 PM
Data Sourced
via MITRE·05:11 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-45109?

CVE-2026-45109 is classified as a moderate severity vulnerability in specific versions of the Next.js framework.

2

How do I fix CVE-2026-45109?

To mitigate CVE-2026-45109, upgrade to Next.js version 16.2.6 or version 15.5.18.

3

Which versions of Next.js are affected by CVE-2026-45109?

CVE-2026-45109 affects Next.js versions from 16.0.0 to 16.2.6 and from 15.2.0 to 15.5.18.

4

What components are involved in CVE-2026-45109?

CVE-2026-45109 involves the middleware.ts file in Next.js when using Turbopack.

5

Is CVE-2026-45109 related to any previous vulnerabilities?

CVE-2026-45109 is related to CVE-2026-44575 as it concerns a fix that did not apply as intended.

Company

Resources

Contact

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