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Fencer Intel
critical 9.6

CVE-2026-49481 json

UpSnap vulnerable to Remote Code Execution via IP Field Template Injection in wake_cmd/shutdown_cmd

published 5mo ago modified 18d ago also EUVD-2026-57694 , GHSA-6mc7-6948-w5h4

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository seriousm4x/UpSnap. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
9.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

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 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.

Patch / fix

Is CVE-2026-49481 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2mo ago

Exploit prediction

1.48% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected products

  • seriousm4x UpSnap

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of seriousm4x/UpSnap published their own advisory on GitHub. Reviewed sources take precedence over it.