Race condition in Next.js - CVE-2025-32421
Published: May 16, 2025 / Updated: November 28, 2025
Vulnerability identifier: #VU109239
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:L/SA:N/E:P/U:Clear
CVE-ID: CVE-2025-32421
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: vercel
Affected software:
Next.js
Next.js
Detailed vulnerability description
The vulnerability allows a remote attacker to gain access to sensitive information or perform spoofing attack.
The vulnerability exists due to a race condition within the Pages Router. A remote attacker can exploit the race and obtain pageProps data instead of standard HTML code and poison the CDN cache by injecting the response body from a non-cacheable data request (?__nextDataRequest=1) into a normal request that retains cacheable headers, such as Cache-Control: public, max-age=300.
How to mitigate CVE-2025-32421
Install updates from vendor's website.