CVE-2025-26409Public exploit

Root shell access via unprotected serial bootloader

Published Feb 11, 2025 · Updated Nov 3, 2025

Improper access control in Wattsense Bridge before 6.4.1 allows physically proximate attackers to obtain a root shell through PCB serial pins. The exposed 3.3 V UART header accepts a key during startup, enters U-Boot, and permits boot arguments to be changed so Linux starts /bin/sh as root. Exploitation requires opening the enclosure, reaching the PCB, and attaching a serial adapter; root access permits persistent account and device-behavior changes.

CVSS severity6.8
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Wattsense Bridge before 6.4.1 allows physically proximate attackers to obtain a root shell through PCB serial pins. The exposed 3.3 V UART header accepts a key during startup, enters U-Boot, and permits boot arguments to be changed so Linux starts /bin/sh as root. Exploitation requires opening the enclosure, reaching the PCB, and attaching a serial adapter; root access permits persistent account and device-behavior changes.

The record

CVE
CVE-2025-26409
Published
Feb 11, 2025
Updated
Nov 3, 2025
Vendor
Wattsense
Product
Wattsense Bridge
Classifications
CWE-1191, CWE-1299, T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <6.4.1

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

Wattsense · Wattsense Bridgeversion=0 <6.4.1

Published CVSS scores

6.8CISA-ADPCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1191On-Chip Debug and Test Interface With Improper Access Control
CWE-1299Missing Protection Mechanism for Alternate Hardware Interface
T1200Hardware Additions

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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