CVE-2025-20393
Improper Input Validation in Cisco Multiple Products. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 17 December 2025.
- Product
- Cisco Multiple Products
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- No known use in ransomware campaigns
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
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.
More from Cisco this year.
- CVE-2026-76418 Unchecked Return Value to NULL Pointer Dereference, added
- CVE-2026-76519 Relative Path Traversal, added
- CVE-2026-76504 Hex Encoding, added
- CVE-2026-76460 Incorrect Use of Privileged APIs, added
- CVE-2026-76461 SQL Injection, added
- CVE-2026-20079 Firewall Management Center Authentication Bypass Using an Alternate Path or Channel, added
- CVE-2026-20349 Heap Inspection, added
- CVE-2026-20316 Secure Firewall Management Center Use of Hard-coded Password, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.