---
id: CVE-2026-49481
title: UpSnap is a wake on lan web app
summary: >-
  UpSnap is a wake on lan web app. Versions prior to 5.4.0 have an OS command
  injection vulnerability in the UpSnap’s device management functionality due to
  the presence of unsafe shell command template interpolation using the ip and
  the m…
severity: critical
cvss: 9.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N'
cwe:
  - CWE-78
published: '2026-08-12'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T20:09:01.757'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-49481'
references:
  - url: 'https://github.com/seriousm4x/UpSnap/releases/tag/5.4.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/seriousm4x/UpSnap/security/advisories/GHSA-6mc7-6948-w5h4
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00882
epssPercentile: 0.57673
ingestedAt: '2026-09-18T20:51:25.605Z'
---

## Overview

UpSnap is a wake on lan web app. Versions prior to 5.4.0 have an OS command injection vulnerability in the UpSnap’s device management functionality due to the presence of unsafe shell command template interpolation using the ip and the mac fields. User-controlled values can be inserted into the wake_cmd and shutdown_cmd templates and executed via /bin/sh -c (Linux) or cmd /C (Windows) without sanitization, resulting in an authenticated Remote Code Execution (RCE). A low-privileged user with permission to create or edit devices can execute arbitrary operating system commands on the UpSnap hosted server. Version 5.4.0 patches the issue.

## Remediation

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