CVE-2025-20393

CRITICAL CISA KEV

CVSS v3

10

CRITICAL

EPSS Score

6.6%

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

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

CISA Known Exploited Vulnerability

Date Added
12/17/2025
Patch Due Date
12/24/2025
Required Action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Technical Details

CVSS v3 Vector
3.1
Published
12/17/2025
Last Modified
1/16/2026

Frequently Asked Questions

What is CVE-2025-20393?

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

Is CVE-2025-20393 actively exploited?

Yes. CVE-2025-20393 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 12/24/2025.

What is the CVSS score for CVE-2025-20393?

CVE-2025-20393 has a CVSS v3 base score of 10 (CRITICAL severity), with vector string 3.1.

Is CVE-2025-20393 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.