CVE-2025-20393

critical Cisco ⚠️ CISA KEV — Exploited in the Wild
CVSS v3 Base Score
10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS Score
6.3%
Exploitation probability in 30 days
Top 9% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Published: December 17, 2025 (147 days ago)
Last Modified: January 16, 2026
Vendor: Cisco

⚠️ CISA Known Exploited Vulnerability

Added to KEV: 2025-12-17
Remediation Due: 2025-12-24 (⚠ 141d overdue)

Description

A vulnerability in the Spam Quarantine feature of Cisco AsyncOS Software for Cisco Secure Email Gateway and Cisco Secure Email and Web Manager could allow an unauthenticated, remote attacker to execute arbitrary system commands on an affected device with root privileges. This vulnerability is due to insufficient validation of HTTP requests by the Spam Quarantine feature. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

CWE

CWE-20

Affected Products

cisco asyncos

References

🔗 sec.cloudapps.cisco.com 🔗 www.cisa.gov