CVE-2026-18678 Kong Mesh: kumactl connects to the control plane without verifying the TLS certificate when no CA is configured
Attackers can intercept API tokens by exploiting disabled TLS verification in kumactl when no CA is configured, allowing unauthorized control plane access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-18678?
CVE-2026-18678 is a medium-severity vulnerability in Kong Mesh, published on 12 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-295
Which versions are affected by CVE-2026-18678?
How do I fix CVE-2026-18678?
Apply the vendor's patch.
Is CVE-2026-18678 being exploited?
There is no known exploitation of CVE-2026-18678 in the wild and no public exploit code.
Sources
Also known as GHSA-26pg-x7g5-9g43.