CVE-2026-64641: vercel next.js · Excessive Iteration
Affects vercel next.jsSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 16.2.11 or 15.5.21 soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-07-27.
- Patch
- Available – fixed in 16.2.11, 15.5.21
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade vercel next.js to 16.2.11 or 15.5.21.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| vercelnext.js | Affected
| Fixed in
|
| vercelnext.js | Affected
| Fixed in
|
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, crafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process. This issue has been fixed in versions 15.5.21 and 16.2.11.
References
- github.com/vercel/next.js/security/advisories/GHSA-m99w-x7hq-7vfj (opens in a new tab)
- github.com/vercel/next.js/pull/96013 (opens in a new tab)
- github.com/vercel/next.js/commit/019628571641dec57aaf349ba0c360e3964e6f12 (opens in a new tab)
- github.com/vercel/next.js/releases/tag/v15.5.21 (opens in a new tab)
- github.com/vercel/next.js/releases/tag/v16.2.11 (opens in a new tab)