VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVReported exploited: VulnCheck KEV since Published CVSS 9.1 criticalEPSS 99.2% probability of exploitation in 30 days
vercel

CVE-2025-29927: Authorization Bypass in Next.js Middleware

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of .

VulnCheck KEV lists it since . It cites 82 public reports, the first from . VulnCheck's own honeypots also recorded exploitation attempts.

How likely is exploitation in the next 30 days?
99.2%

EPSS score, percentile 99.9 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
9.1 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

  • >= 11.1.4, < 12.3.5
  • >= 14.0.0, < 14.2.25
  • >= 15.0.0, < 15.2.3
  • >= 13.0.0, < 13.5.9

Versions by product

Source: CISA KEV 2026.10.29, as of ; VulnCheck KEV, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

Description

Authorization Bypass in Next.js Middleware

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.

Source: CVE List, as of . About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Versions by product, as listed in the CVE record (1 product)
vercel next.js
StatusVersions
Affected>= 11.1.4, < 12.3.5
Affected>= 14.0.0, < 14.2.25
Affected>= 15.0.0, < 15.2.3
Affected>= 13.0.0, < 13.5.9

Source: CVE List, as of . About the data.

Weakness

CWE-285

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published
CVE record last updated

References

5