CVE-2026-44578

Medium

Elevated severity or exploit probability.

CVSS base

8.6 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS — probability of exploitation (30 days)

38.9%

98.5th percentile

CISA KEV

Not listed

Weakness / dates

CWE-918

Published 2026-05-13 · modified 2026-08-13

CVSS breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	C	Changed
Confidentiality	H	High
Integrity	N	None
Availability	N	None

Timeline

2026-05-13 — Published (NVD)
2026-08-13 — Last modified (NVD)

Description

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 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.

Affected

vercel

References

Official: NVD · CVE.org