CVE-2026-64648Medium▾ SunlitNext.js: Cache confusion of response bodies for requests with bodies
▾ Sunlit zone — Low / medium · no exploitation signal
impact 27.5 · likelihood 0.1 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 28.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via GHSA
0.5%
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.
Safe: fetch(new Request(init), init)
Unsafe: fetch(new Request(init), aDifferentInit)
No workaround exists besides upgrading. Applications using Pages Router are not vulnerable.
next >= 13.0.0, < 15.5.21next >= 16.0.0, < 16.2.11Upgrade to a patched release:
next 15.5.21next 16.2.11Connected by shared product, vendor, weakness, or advisory.
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