CVE-2026-64647

Low

No strong exploitation signal.

CVSS base

5.4 MEDIUM

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

EPSS — probability of exploitation (30 days)

0.4%

28.8th percentile

CISA KEV

Not listed

Weakness / dates

CWE-116

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

CVSS breakdown

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

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	R	Required
Scope	U	Unchanged
Confidentiality	L	Low
Integrity	L	Low
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, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for 삃삃 and 섄섄 in the request body would share the same cache. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected

vercel

References

Official: NVD · CVE.org