WAF – WAF Release – 2026-08-26 – Emergency

This emergency release updates an existing Next.js remote code execution rule to identify CVE-2026-75604 and adds a new rule for remote code execution in the Next.js Image Optimizer via crafted AVIF images.

Key Findings

  • CVE-2026-75604 affects Windows-hosted Next.js applications using both the Pages Router and App Router without Cache Components and can lead to unauthenticated remote code execution.

  • GHSA-2xp9-vwfh-vxw4 affects the Next.js Image Optimizer and can lead to unauthenticated remote code execution when it optimizes an attacker-controlled AVIF image.

Impact

Next.js recommends updating to version 16.3.3 or 15.5.24 to address these vulnerabilities.

Ruleset Rule ID Legacy Rule ID Description Previous Action New Action Comments
Cloudflare Managed Ruleset N/A Next.js – Remote Code Execution – CVE:CVE-2026-75604 Block N/A Rule metadata description refined. Detection unchanged.
Cloudflare Managed Ruleset N/A Next.js – Image Optimizer Remote Code Execution via Crafted AVIF N/A Block This is a new detection.

Source: Cloudflare

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