CVE-2026-25818

CRITICAL EPSS 3.9%

Published Mar 13, 20263mo ago · Modified Apr 27, 20262mo ago

9.1 CVSS 3.1

Critical

Published Mar 13, 2026 3mo ago

Last Modified Apr 27, 2026 2mo ago

Description

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have weak entropy for authentication cookies, allowing an attacker with a stolen session cookie to find the user password by brute-forcing an encryption parameter.

CVSS Details

Base Score

9.1

Exploitability

3.9

Impact

5.2

Vector string

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector Network

Attack Complexity Low

Privileges Required None

User Interaction None

Scope Unchanged

Confidentiality High

Integrity High

Availability None

Threat Intelligence

EPSS Exploit Probability

3.9% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-315

References 2

hmsnetworks.blob.core.windows.net https://hmsnetworks.blob.core.windows.net/nlw/docs/default-source/products/cybersecurity/security-advisory/hms-security-advisory-2026-03-09-001---ewon-several-flexy-and-cosy--vulnerabilities.pdf?sfvrsn=f7c027b8_13
hms-networks.com https://www.hms-networks.com/p/flexy20500-00ma-ewon-flexy-205

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.