Buffer overflow in N/a

CVE-2026-25823

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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 59.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-25823: held from 0.007 to 0.009.

EPSS over last 30 days · oldest: 0.007 · newest: 0.009 · change: +0.002

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-25823?
CVE-2026-25823 is a critical-severity vulnerability in N/a, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-03-13.
How severe is CVE-2026-25823?
Critical severity. CVSS v3 base score is 9.8 out of 10.