How severe is CVE-2025-29927?

CVE-2025-29927 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2025-29927 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 99% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-29927?

CVE-2025-29927 affects Vercel Next.js. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-29927?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-29927 have an EU (EUVD) identifier?

Yes. CVE-2025-29927 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7243.

When was CVE-2025-29927 published?

CVE-2025-29927 was published on 2025-03-21 and last updated on 2026-06-17.

CVE-2025-29927

CVE-2025-29927 is a critical-severity vulnerability in Vercel Next.js with a CVSS 3.x base score of 9.1. Its EPSS exploit-prediction score of 99% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-863.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 99% (100th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-7243
Weakness: CWE-863
Affected product: Vercel Next.js
Published: 2025-03-21
Last modified: 2026-06-17

Description

Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.

Frequently asked questions

What is CVE-2025-29927?: Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.
How severe is CVE-2025-29927?: CVE-2025-29927 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2025-29927 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 99% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-29927?: CVE-2025-29927 affects Vercel Next.js. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-29927?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-29927 have an EU (EUVD) identifier?: Yes. CVE-2025-29927 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7243.
When was CVE-2025-29927 published?: CVE-2025-29927 was published on 2025-03-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*

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