# 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.

- **Severity:** Medium 5.5 (`CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H`)
- **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:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-26pg-x7g5-9g43

## 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 (Improper Certificate Validation)

## 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.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18678 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-18678 in the wild and no public exploit code.

Affected product: Kong Mesh. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18678/ (Markdown: https://insights.sbomify.com/CVE-2026-18678/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18678
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18678
- OSV: https://osv.dev/vulnerability/CVE-2026-18678

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18678/
Summaries are generated and may contain mistakes; the official description above is the record.