CVE-2026-25818

9.1 criticalEPSS 0.1%

Critical (9.1). EPSS 0.1% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.1

9.1 critical

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

EPSS: 0.1% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-31)
CWE: CWE-315
Published: 2026-03-13
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

References

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

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