CVE-2026-44578
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 38.9%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
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.
- CVSS 3.1
- 8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 38.87% probability · 99th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- vercel/next.js
- Source
- security-advisories@github.com
References
- https://github.com/vercel/next.js/security/advisories/GHSA-c4j6-fc7j-m34rMitigation, Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:34608
- https://access.redhat.com/errata/RHSA-2026:37272
- https://access.redhat.com/errata/RHSA-2026:40974
- https://access.redhat.com/errata/RHSA-2026:54435
- https://access.redhat.com/security/cve/CVE-2026-44578
- https://bugzilla.redhat.com/show_bug.cgi?id=2477187
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44578.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.