RCE in Seriousm4x Upsnap

CVE-2026-49481

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.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.015 (72.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 73rd percentile — 72.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-49481: rose from 0.009 to 0.015.

EPSS over last 30 days · oldest: 0.009 · newest: 0.015 · change: +0.006

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-49481?
CVE-2026-49481 is a critical-severity vulnerability in Seriousm4x Upsnap, classified under OS Command Injection. CVSS score: 9.6/10. Published 2026-08-12.
How severe is CVE-2026-49481?
Critical severity. CVSS v3 base score is 9.6 out of 10.