CLEANSTART-2026-PT93351: malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go ...

Q: What conditions are required for exploitation?

An attacker must operate or control a malicious GOPROXY used by the affected environment. The proxy can forge up to two sumdb tiles so that a requested module bypasses the GOSUMDB check and attacker-controlled content is written to the local Go module cache.

Q: What is the impact if exploitation succeeds?

A requested Go module can bypass GOSUMDB verification, and attacker-controlled module content can persist in the local Go module cache. The reported impact includes high confidentiality, integrity, and availability consequences.

Published Nov 11, 2026

Updated

Security vulnerability affects the kubernetes package. A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go module cache.

Affected Software

1 affected componentFixes available

cleanstart/kubernetes<1.34.13-r2

1.34.13-r2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade cleanstart/kubernetes to a version that resolves this vulnerability.
Fixed in 1.34.13-r2

Event History

Nov 11, 2026

Advisory Published

via OSV·12:37 AM

Data Sourced

via OSV·12:37 AM

DescriptionSeverityAffected Software

Child vulnerabilities

Contains the following vulnerabilities.

CVE-2026-56865

Frequently Asked Questions

What conditions are required for exploitation?

An attacker must operate or control a malicious GOPROXY used by the affected environment. The proxy can forge up to two sumdb tiles so that a requested module bypasses the GOSUMDB check and attacker-controlled content is written to the local Go module cache.

What is the impact if exploitation succeeds?

A requested Go module can bypass GOSUMDB verification, and attacker-controlled module content can persist in the local Go module cache. The reported impact includes high confidentiality, integrity, and availability consequences.

CLEANSTART-2026-PT93351: malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go ...

Affected Software

Remediation

Event History

Child vulnerabilities

Frequently Asked Questions

What conditions are required for exploitation?

What is the impact if exploitation succeeds?

Company

Resources

Contact

Frequently Asked Questions

What conditions are required for exploitation?

What is the impact if exploitation succeeds?