CVE-2026-64643

Low

No strong exploitation signal.

CVSS base

5.3 MEDIUM

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

EPSS — probability of exploitation (30 days)

0.5%

42.9th percentile

CISA KEV

Not listed

Weakness / dates

CWE-201

Published 2026-07-27 · modified 2026-07-29

CVSS breakdown

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

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	L	Low
Integrity	N	None
Availability	N	None

Timeline

2026-07-27 — Published (NVD)
2026-07-29 — Last modified (NVD)

Description

Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected

vercel

References

Official: NVD · CVE.org