CVE-2026-25818
Auth cookie entropy weakness enables password recovery from stolen session.
Is CVE-2026-25818 being exploited?
Not confirmed. CVE-2026-25818 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.14% probability of exploitation in the next 30 days.
How severe is CVE-2026-25818?
CVE-2026-25818 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-25818?
Yes. A fix has been recorded for CVE-2026-25818. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-25818 affect?
CVE-2026-25818 affects Ewon Flexy firmware < 15.0s4, Cosy+ firmware < 22.1s6, Cosy+ firmware < 23.0s3. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-25818?
Update to fixed firmware versions (15.0s4, 22.1s6, 23.0s3+).
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
With a stolen session cookie, attacker can brute-force the encryption parameter to reveal user passwords and take control.
Immediate action required