Medium severity · published Jul 27, 2026
CVE-2026-64646
Next.js: Unbounded Server Action payload in Edge runtime
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
Next.js is a React framework for building full-stack web applications. In versions 13.0.0 through 15.5.20 and 16.0.0 through 16.2.10, requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive memory consumption if that Server Actions uses the Edge runtime. This issue has been fixed in versions 15.5.21 and 16.2.11.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
next.js · vercel
>= 13.0.0 < 15.5.21; >= 16.0.0, < 16.2.11 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-64646
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-64646
Patch
https://github.com/vercel/next.js/commit/57c31f724d746e86a9e8b92aa8be538a922446a4
Patch
https://github.com/vercel/next.js/commit/9a4651e754f70b12e397694ffc41f44c3ba8cc17
Product
https://github.com/vercel/next.js/releases/tag/v15.5.21
Product
https://github.com/vercel/next.js/releases/tag/v16.2.11
Vendor Advisory
https://github.com/vercel/next.js/security/advisories/GHSA-4c39-4ccg-62r3
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