# CVE-2026-90647: Security feature bypass in ASE2000 V2 Communication Test Set

> A network attacker can bypass TLS certificate validation in the Kalkitech ASE2000 to perform Man-in-the-Middle attacks on protected communications.

- **Severity:** Critical 9.1 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-gcc5-22r7-2jf2

## What is CVE-2026-90647?

CVE-2026-90647 is a critical vulnerability in Kalkitech ASE2000 V2 Communication Test Set, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

ASE/Kalkitech ASE2000 V2 Communication Test Set 2.35 through 2.37 on Windows contains an improper certificate validation vulnerability in the IEC 60870-5-104 TLS client (Task Mode). This allows a network-positioned attacker to bypass certificate validation via a certificate with multiple simultaneous faults, enabling a Man-in-the-Middle attack on protected communications.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-90647?


## How do I fix CVE-2026-90647?

No fix has been published for CVE-2026-90647 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90647 being exploited?

There is no known exploitation of CVE-2026-90647 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90647 and fix it if it is affected.

What it is: CVE-2026-90647 is a critical vulnerability in Kalkitech ASE2000 V2 Communication Test Set, published on 12 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90647 in the wild and no public exploit code.

Affected product: Kalkitech ASE2000 V2 Communication Test Set. 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-2026-90647/ (Markdown: https://insights.sbomify.com/CVE-2026-90647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90647
- OSV: https://osv.dev/vulnerability/CVE-2026-90647

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-90647/
Summaries are generated and may contain mistakes; the official description above is the record.