CVE-2026-44578 Scanner

Next.js is a popular web development framework developed by Vercel, widely utilized by developers for building server-side rendered React applications. Its simplicity and flexibility have made it a go-to choice for both small and large scale web projects. Developers of various expertise levels leverage it for its powerful features such as automatic code splitting, static site generation, and API support. The framework is an integral tool for web developers seeking to create high-performance, SEO-friendly web applications. Companies often rely on Next.js to produce dynamic, scalable websites and applications that improve user experience and engagement. Next.js continues to innovate, continuously expanding its functionalities and integration capabilities with other technologies.

Server-side request forgery (SSRF) is a critical vulnerability that occurs when an attacker manipulates a server into making requests to unintended locations. SSRF vulnerabilities are dangerous because they can be used to probe and interact with otherwise inaccessible internal services or network segments. This weakness can also be exploited to retrieve sensitive metadata information from cloud service providers' endpoints. In the context of Next.js, SSRF vulnerabilities allow attackers to craft malicious WebSocket upgrade requests to force the Node.js server to proxy requests to arbitrary destinations. This type of vulnerability poses significant security risks as attackers bypass typical security mechanisms, leading to unauthorized access and potential exploitation of internal resources.

This specific SSRF vulnerability in Next.js emerges due to the handling of WebSocket upgrade requests in the Node.js server component. By utilizing crafted WebSocket headers, attackers are able to manipulate the server into forwarding requests to both internal and external services. The vulnerability is particularly severe as it enables proxying to cloud metadata endpoints, a common target for SSRF attacks. Attackers can construct request payloads containing malicious URLs or headers in order to extract sensitive information or perform further enumeration. Key parameters manipulated during the SSRF attempt include the 'Host' and 'Upgrade' headers within the HTTP requests. Vigilance is required to detect malicious attempts and prevent exploitation through proper configuration and version updates.

The exploitation of this SSRF vulnerability in Next.js could lead to grave security implications. If an attacker successfully leverages this vulnerability, they can access sensitive internal resources not publicly exposed on the internet. This could include confidential data, internal applications, and metadata services on cloud platforms. Unintended access may potentially help attackers enumerate and map internal network structures, laying the groundwork for subsequent attacks. Additionally, it could result in unauthorized data disclosure or manipulation, degrading trust and security integrity of the affected application. Attackers might also pivot from this entry point to launch further attacks such as privilege escalation or lateral movement within the network.

REFERENCES

• https://github.com/advisories/GHSA-c4j6-fc7j-m34r
• https://nextjs.org/blog/next-15-5-16
• https://app.hacktron.ai/disclosed/scans/web_dmVyY2VsL25leHQtanMtbWlycm9y_1774994038380_2hfQkCKG/findings/66f26e9e-a71f-4997-85be-a0b5fa3b7d89