CVE-2026-64648: CWE-524: Use of Cache Containing Sensitive Information in vercel next.js
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 only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.
AI Analysis
Technical Summary
In Next.js 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 incorrectly return a cached response body from a different request to the same URL but with a different request body. This causes sensitive data leakage in POST response bodies to unauthorized requests. The problem occurs when fetch is called with a Request object and a different init object, causing the cache to serve stale or incorrect data. The vulnerability is addressed in versions 15.5.21 and 16.2.11.
Potential Impact
Confidential data included in the response body of POST requests may be leaked to unauthorized requests due to improper caching behavior in the affected Next.js versions. This can expose sensitive information to unintended parties, potentially leading to data breaches or information disclosure.
Mitigation Recommendations
Upgrade Next.js to version 15.5.21 or later, or 16.2.11 or later, where this caching issue has been fixed. Ensure that fetch calls use consistent init parameters when passing a Request object to avoid triggering the vulnerability. Patch status is confirmed fixed in these versions.
CVE-2026-64648: CWE-524: Use of Cache Containing Sensitive Information in vercel next.js
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 only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.
CVSS v4.0
Score 6.0medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Next.js 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 incorrectly return a cached response body from a different request to the same URL but with a different request body. This causes sensitive data leakage in POST response bodies to unauthorized requests. The problem occurs when fetch is called with a Request object and a different init object, causing the cache to serve stale or incorrect data. The vulnerability is addressed in versions 15.5.21 and 16.2.11.
Potential Impact
Confidential data included in the response body of POST requests may be leaked to unauthorized requests due to improper caching behavior in the affected Next.js versions. This can expose sensitive information to unintended parties, potentially leading to data breaches or information disclosure.
Mitigation Recommendations
Upgrade Next.js to version 15.5.21 or later, or 16.2.11 or later, where this caching issue has been fixed. Ensure that fetch calls use consistent init parameters when passing a Request object to avoid triggering the vulnerability. Patch status is confirmed fixed in these versions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-68g3-v927-f742
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-64648"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6a616bcd9c2644c7f80dbd89
Added to database: 07/23/2026, 01:18:05 UTC
Last enriched: 07/30/2026, 15:27:32 UTC
Last updated: 09/04/2026, 10:52:10 UTC
Views: 129
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