CVE-2026-44578

highpriority · track · 22EPSS 0.355 · 98 %ileexploit · PoCDEEURUUS
grimoire priorityP1 · Urgent
Exploitable?
Public exploit
8 exploits · PoC
Likely / severe?
35.5% (98th) EPSS
CVSS 8.6 · high
Is it mine?
13 products
Check your exposure
Who says so?
6 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

8.6
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.6highAV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Nsecondary · ENISA EU
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Nsecondary · security-advisories@github.comexploitability 3.9 · impact 4
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Nsecondaryexploitability 3.9 · impact 4
v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Nsecondary · OSV
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-918USCWE-918USCWE-918US
04

exploits (8)

Public proof-of-concept and weaponised exploit code.

05

affected products (13)

Products and version ranges known to be affected.

06

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-1401Vercel Next.js: Mehrere SchwachstellenDeutsch2026-05-06csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in Vercel Next.js ausnutzen, um Sicherheitsvorkehrungen zu umgehen, Cross-Site-Scripting-Angriffe durchzuführen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

  • GHSA-c4j6-fc7j-m34rNext.js vulnerable to server-side request forgery in applications using WebSocket upgrades2026-05-11ghsa · osvUS

    ### Impact 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. ### Fix We now apply the same safety checks to WebSocket upgrade handling that already existed for normal HTTP requests, so upgrade requests are only proxied when routing has explicitly marked them as safe external rewrites. ### Workarounds If you cannot upgrade immediately, do not expose the origin server directly to untrusted networks. If WebSocket upgrades are not required, block them at your reverse proxy or load balancer, and restrict origin egress to internal networks and metadata services where possible.

07

also known as (5)

Other names and identifiers for this entity.

08

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundnvdosvNVDCVE.orgMITRE
published 2026-05-13modified 2026-10-26
09

references (11)

External citations — patches, advisories, analysis.

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