CVE-2026-64641

Q: How do I fix CVE-2026-64641?

Upgrade next.js to 15.5.21 or later.

Q: Is CVE-2026-64641 being actively exploited?

Not that we know of. CVE-2026-64641 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.60% is the estimated probability that it will be exploited in the next 30 days. That is higher than 45% of all scored CVEs.

Q: How severe is CVE-2026-64641?

CVE-2026-64641 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-64641 affect?

Published advisories record a fix for next.js (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

HIGH

7.5

CVSS v3

NVD

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.

CWE-834

How to fix

Remediation Available

next.jsNVD

Affected:>= 13.0.0, < 15.5.21Fixed in:15.5.21CVE-2026-64641derived from NVD

Affected:>= 16.0.0, < 16.2.11Fixed in:16.2.11CVE-2026-64641derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.60%probability of exploitation in 30 days

45thpercentile

Moderate risk: more likely to be exploited than 45% of all known CVEs.

References

Patch2

Vendor Advisory1

github.com

Release Notes2

Related Vulnerabilities

Other CWE-834 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2021-35515	High	7.5	12%	-	Fix
CVE-2021-39924	High	7.5	4.9%	-	Fix
CVE-2023-1993	Medium	6.3	4.1%	-	Fix
CVE-2018-14342	High	7.5	3.7%	-	Fix
CVE-2020-14303	High	7.5	3.5%	-	Fix
CVE-2018-9133	Medium	6.5	3.2%	-	Fix

Common questions

How do I fix CVE-2026-64641?

Upgrade next.js to 15.5.21 or later.

Is CVE-2026-64641 being actively exploited?

Not that we know of. CVE-2026-64641 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.60% is the estimated probability that it will be exploited in the next 30 days. That is higher than 45% of all scored CVEs.

How severe is CVE-2026-64641?

CVE-2026-64641 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-64641 affect?

Published advisories record a fix for next.js (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-64641

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-29.