CLEANSTART-2026-DA26397: When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) can consume an excessive amount of CPU

Q: What level of attacker access is required?

The vulnerability is network-reachable and requires neither prior privileges nor user interaction. An unauthenticated remote attacker can trigger the condition.

Q: What is the expected security impact?

The stated impact is high availability impact from excessive CPU consumption. No confidentiality or integrity impact is indicated.

Q: Which deployments should be prioritized for triage?

The affected software listed for this advisory is cleanstart/kubernetes and cleanstart/argo-workflows. The underlying issue affects multiple packages associated with FileServer(FS), ServeContent, and ServeFile(FS).

Published Nov 11, 2026

Updated

CVE-2026-78667 affects multiple packages. When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) can consume an excessive amount of CPU. See references for individual vulnerability details.

Affected Software

3 affected componentsFixes available

cleanstart/kubernetes<1.34.11-r0

1.34.11-r0

cleanstart/kubernetes<1.34.13-r2

1.34.13-r2

cleanstart/argo-workflows<4.1.6-r1

4.1.6-r1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade cleanstart/kubernetes to a version that resolves this vulnerability.
Fixed in 1.34.11-r0
Upgrade
Upgrade cleanstart/kubernetes to a version that resolves this vulnerability.
Fixed in 1.34.13-r2
Upgrade
Upgrade cleanstart/argo-workflows to a version that resolves this vulnerability.
Fixed in 4.1.6-r1

Event History

Nov 11, 2026

Advisory Published

via OSV·12:39 AM

Data Sourced

via OSV·12:39 AM

DescriptionSeverityAffected Software

Child vulnerabilities

Contains the following vulnerabilities.

CVE-2026-78667

Frequently Asked Questions

What level of attacker access is required?

The vulnerability is network-reachable and requires neither prior privileges nor user interaction. An unauthenticated remote attacker can trigger the condition.

What is the expected security impact?

The stated impact is high availability impact from excessive CPU consumption. No confidentiality or integrity impact is indicated.

Which deployments should be prioritized for triage?

The affected software listed for this advisory is cleanstart/kubernetes and cleanstart/argo-workflows. The underlying issue affects multiple packages associated with FileServer(FS), ServeContent, and ServeFile(FS).

CLEANSTART-2026-DA26397: When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) can consume an excessive amount of CPU

Affected Software

Remediation

Event History

Child vulnerabilities

Frequently Asked Questions

What level of attacker access is required?

What is the expected security impact?

Which deployments should be prioritized for triage?

Company

Resources

Contact

Frequently Asked Questions

What level of attacker access is required?

What is the expected security impact?

Which deployments should be prioritized for triage?