Vercel - Authorization Bypass (CVE-2025-29927)
56Exploiting IPs reported
In NextJS React framework prior to 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
CrowdSec analysis
CVE-2025-29927 is a high-severity vulnerability affecting the NextJS React framework, which allows attackers to bypass authorization checks when these controls are enforced through application middleware.
CrowdSec has been tracking this vulnerability and its exploits since 24th of March 2025.
CrowdSec network data shows that most actors exploiting CVE-2025-29927 rely on broad, untargeted scans with minimal filtering. The activity is largely automated and opportunistic in nature. In addition, according to the CrowdSec network, attack volume against CVE-2025-29927 has dipped slightly compared to the previous week. Although still commonly targeted, the decline suggests a cooling-off period. Long-term relevance remains, but attention is waning.
Attack patterns are tailored towards application endpoints that rely on middleware-based authorization within NextJS deployments.
Exploitation
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Protection
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Blocklist
With our advanced worldwide network detection, CrowdSec can provide a list of IPs known for exploiting the vulnerability.
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