---
id: CVE-2026-78862
title: >-
  An issue in Mercusys AC12 V2 allows a local attacker to execute arbitrary code
  via the UART serial interface on the printed circuit board (PCB)
summary: >-
  An issue in Mercusys AC12 V2 allows a local attacker to execute arbitrary code
  via the UART serial interface on the printed circuit board (PCB)
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-1299
published: '2026-10-05'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T18:16:56.517'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-78862'
references:
  - url: 'http://ac12.com'
    label: cve@mitre.org
  - url: 'http://mercusys.com'
    label: cve@mitre.org
  - url: >-
      https://threadpoolx.gitbook.io/docs/cve/mercusys-ac12-v2-security-advisory/unprotected-physical-debug-interface-uart
    label: cve@mitre.org
  - url: >-
      https://threadpoolx.gitbook.io/docs/cve/mercusys-ac12-v2-security-advisory/unprotected-physical-debug-interface-uart
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-06T16:54:36.278117Z'
ingestedAt: '2026-10-05T20:32:56.655Z'
epss: 0.00261
epssPercentile: 0.1772
---

## Overview

An issue in Mercusys AC12 V2 allows a local attacker to execute arbitrary code via the UART serial interface on the printed circuit board (PCB)

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.