How severe is CVE-2026-64641?

CVE-2026-64641 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-64641 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-64641?

CVE-2026-64641 affects Vercel Next.js. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-64641?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-64641 published?

CVE-2026-64641 was published on 2026-07-27 and last updated on 2026-07-29.

CVE-2026-64641

CVE-2026-64641 is a high-severity vulnerability in Vercel Next.js with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-834.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.2
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-834
Affected product: Vercel Next.js
Published: 2026-07-27
Last modified: 2026-07-29

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.

Frequently asked questions

What is CVE-2026-64641?: 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.
How severe is CVE-2026-64641?: CVE-2026-64641 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-64641 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-64641?: CVE-2026-64641 affects Vercel Next.js. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-64641?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-64641 published?: CVE-2026-64641 was published on 2026-07-27 and last updated on 2026-07-29.

References

Affected products (1)

cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:*

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