REDHAT-BUG-2477188: High severity Vercel Next.js vulnerability
Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.16 and 16.2.5, App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check. This vulnerability is fixed in 15.5.16 and 16.2.5.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 15.5.16 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 16.2.5
Event History
Frequently Asked Questions
What is the severity of REDHAT-BUG-2477188?
The severity of REDHAT-BUG-2477188 is high, rated at 7.
How do I fix REDHAT-BUG-2477188?
To fix REDHAT-BUG-2477188, update Next.js to version 15.5.16 or later, or 16.2.5 or later.
What versions are affected by REDHAT-BUG-2477188?
REDHAT-BUG-2477188 affects Next.js versions from 15.2.0 up to but not including 15.5.16 and 16.2.5.
What type of vulnerability is REDHAT-BUG-2477188?
REDHAT-BUG-2477188 is a security vulnerability related to unauthorized access in Next.js applications.
When was REDHAT-BUG-2477188 published?
REDHAT-BUG-2477188 was published on May 13, 2026.