Vulnerability · Published Mar 12, 2026 · Assigned by mitre
CVE-2026-25823
Critical 9.8
In plain English
A critical-severity stack buffer overflow in the affected software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 55% of all known vulnerabilities).
Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.8%top 44.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
Weakness: CWE-121 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H