SB2025051603 - Cache poisoning in Next.js

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2025-32421)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://github.com/vercel/next.js/security/advisories/GHSA-qpjv-v59x-3qc4
• https://vercel.com/changelog/cve-2025-32421