CVE-2026-18678: kumactl connects to control plane without verifying TLS certificate when no CA is configured

CVE-2026-18678 · Severity: medium · CVSS 4 · Published 2026-08-12

When an operator adds an HTTPS control plane profile to kumactl without providing a CA certificate, kumactl disables TLS verification and sends API tokens over the unverified connection.

An attacker on the network path between the operator and the control plane can intercept user or admin API tokens and then act against the control plane as that user.

Technologies: github.com/kumahq/kuma (Go), github.com/kumahq/kuma/v2 (Go). Vendors: Go.

Quick answers

Is CVE-2026-18678 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-18678 being exploited in the wild.
How severe is CVE-2026-18678?
Medium severity, with a CVSS score of 4, published 12 August 2026.
Which products and versions are affected?
github.com/kumahq/kuma (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.8.1; github.com/kumahq/kuma/v2 (Go) SEMVER:introduced=0,fixed=2.7.26, SEMVER:introduced=0,fixed=2.7.26,introduced=2.9.13,fixed=2.11.14,introduced=2.12.4,fixed=2.12.11,introduced=2.13.0,fixed=2.13.7.
Is there a fix for CVE-2026-18678?
Yes. github.com/kumahq/kuma/v2 (Go): upgrade to 2.13.7, 2.7.26 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-18678?
Check whether you run github.com/kumahq/kuma (Go) or github.com/kumahq/kuma/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/kumahq/kuma/v2 (Go): upgrade to 2.13.7, 2.7.26 or later
    go get github.com/kumahq/kuma/v2@v2.13.7

Affected products

  • github.com/kumahq/kuma (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.8.1
  • github.com/kumahq/kuma/v2 (Go) SEMVER:introduced=0,fixed=2.7.26, SEMVER:introduced=0,fixed=2.7.26,introduced=2.9.13,fixed=2.11.14,introduced=2.12.4,fixed=2.12.11,introduced=2.13.0,fixed=2.13.7

Identifiers

  • CVE-2026-18678
  • CVE-2026-50166
  • GHSA-v95x-xhq5-4929
  • GO-2026-6010

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.