Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NSummary
CVE-2026-44578 is a high-severity SSRF (CWE-918) vulnerability in Vercel Next.Js. Its CVSS base score is 8.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
Next.js, the React framework for full-stack web applications, contains a server-side request forgery vulnerability tracked as CVE-2026-44578. The flaw affects self-hosted deployments that use the built-in Node.js server in versions 13.4.13 through 15.5.15 and 16.2.4; Vercel-hosted instances are unaffected. An attacker can supply a crafted WebSocket upgrade request that causes the server to proxy traffic to arbitrary internal or external destinations, exposing services or cloud metadata endpoints. The issue carries a CVSS 3.1 score of 8.6 and is classified under CWE-918.
Because the attack requires no authentication and can be launched over the network, any remote adversary who can reach a vulnerable Next.js instance can leverage it to reach otherwise inaccessible resources. Exploitation does not depend on user interaction and can result in high-impact confidentiality breaches without affecting integrity or availability.
The referenced GitHub advisory GHSA-c4j6-fc7j-m34r states that the vulnerability is resolved in Next.js 15.5.16 and 16.2.5. Administrators should upgrade to one of these patched releases; no other mitigations are described in the advisory. The associated EPSS score has remained flat at 0.0722 with no material increase since disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-30080
Vulnerability Data
Next.js is a React framework for building full-stack web applications. From 13.4.13 to before 15.5.16 and 16.2.5, self-hosted applications using the built-in Node.js server can be vulnerable to server-side request forgery through crafted WebSocket upgrade requests. An attacker can cause…
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the server to proxy requests to arbitrary internal or external destinations, which may expose internal services or cloud metadata endpoints. Vercel-hosted deployments are not affected. This vulnerability is fixed in 15.5.16 and 16.2.5.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.6V1.5.3V5.3.2V10.4.7
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.