CVE-2021-23241: Mercusys Mercury x18g Firmware

Medium severity, CVSS 5.3. EPSS: 13.3% chance of exploitation in the next 30 days.

MERCUSYS Mercury X18G 1.0.5 devices allow Directory Traversal via ../ in conjunction with a loginLess or login.htm URI (for authentication bypass) to the web server, as demonstrated by the /loginLess/../../etc/passwd URI.

Affected products

• Mercusys Mercury x18g Firmware: version 1.0.5 only

Published 2021-01-07. Last modified 2026-06-17.