CVE-2026-25823

CRITICAL

HMS Networks Ewon Flexy <15.0s4 - Buffer Overflow

Title source: llm

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 a stack buffer overflow that leads to a Denial of Service, which can also be exploited to achieve Unauthenticated Remote Code Execution.

References (2)

[Various Sources] 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

[Various Sources] https://www.hms-networks.com/p/flexy20500-00ma-ewon-flexy-205

Scores

CVSS v3 9.8

EPSS 0.0028

EPSS Percentile 51.2%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact total

Details

CWE

CWE-121

Status published

Published Mar 13, 2026

Tracked Since Mar 14, 2026