ClosedPatched

Cisco Multiple Products: Multiple Products Improper Input Validation Vulnerability

Cisco Multiple Products

Cisco Secure Email Gateway, Secure Email, AsyncOS Software, and Web Manager appliances contains an improper input validation vulnerability that allows threat actors to execute arbitrary commands with root privileges on the underlying operating system of an affected appliance. Added to CISA KEV on 2025-12-17.

Why this severity: CVSS 10.0 (CNA, v3.1); actively exploited (CISA KEV)

Started: Dec 17, 2025
Closed: Dec 17, 2025
CVE: CVE-2025-20393

Follow this incident

Updated Dec 17, 2025

Affected

See vendor advisory / CISA notes (versions not always listed in KEV feed)

Fixed in

See vendor advisory linked in sources

Timeline1

Dec 17, 2025
CISA added CVE-2025-20393 to the KEV catalog (due 2025-12-24).

Advisories3

Notes & caveats

Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025).

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