SB2025070417 - Cache poisoning attack in Next.js
Published: July 4, 2025
Security Bulletin ID
SB2025070417
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Input validation error (CVE-ID: CVE-2025-49005)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to perform a cache poisoning attack.
The vulnerability exists due to omission of Vary HTTP header when creating cache data in App Router. A remote attacker can force the application to cache RSC payloads and serve them in place of HTML code under specific conditions involving middleware and redirects.
Remediation
Install update from vendor's website.
References
- https://github.com/vercel/next.js/commit/ec202eccf05820b60c6126d6411fe16766ecc066
- https://github.com/vercel/next.js/issues/79346
- https://github.com/vercel/next.js/releases/tag/v15.3.3
- https://github.com/vercel/next.js/security/advisories/GHSA-r2fc-ccr8-96c4
- https://vercel.com/changelog/cve-2025-49005