A vulnerability exists in Chromium-based browsers and Safari concerning Cross-Origin Resource Sharing (CORS) headers. This allows attackers to manipulate CORS policies in conjunction with DNS rebinding attacks. The exploit enables arbitrary requests to services on any port, bypassing intended CORS restrictions. When a website needs to access resources from another, CORS policies are typically used to regulate this. However, misconfigurations in CORS can be exploited. DNS rebinding attacks leverage the fact that hostnames can be pointed to any IP address. Attackers trick victims into visiting malicious sites, which then scan local networks for services. The malicious site can then rebind its hostname to a target service's IP address. This allows the attacker's site to inherit the target's relaxed CORS policy, facilitating data exfiltration. Mozilla has assigned CVE-2025-8036 to this vulnerability. The potential impact includes exposure of private networks and unauthorized access to sensitive data. Users should update their browsers to the latest versions for security patches.