Remote code execution via React Server Components in Next.js

This security bulletin contains one critical risk vulnerability.

EUVDB-ID: #VU119104

Risk: Critical

CVSSv4.0:

8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Red]

CVE-ID:
CVE-2025-66478

CWE-ID:
CWE-502 – Deserialization of Untrusted Data

Exploit availability:
No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insecure input validation when processing serialized data within the React’s App Router. A remote non-authenticated attacker can send specially crafted HTTP request to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, vulnerability in the react server component is tracked as a separate vulnerability #VU119103 (CVE-2025-55182).

Mitigation

Install updates from vendor’s website.

Vulnerable software versions

Next.js:
15.0.0 – 16.0.6

CPE2.3

External links

github.com/vercel/next.js/security/advisories/GHSA-9qr9-h5gf-34mp

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.