Critical 10.0Known exploited (CISA KEV)Published Dec 17, 2025

CVE-2025-20393Cisco Secure Email Gateway and Cisco Secure Email and Web Manager Remote Command Execution Vulnerability

Updated under an hour ago (2026-10-19 04:50 UTC)

Does this affect you?

It affects Cisco Secure Email and 2 other products. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Dec 17, 2025; federal agencies had to remediate by Dec 24, 2025. Treat that date as your deadline.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Cisco Secure Email

Exploited in the last 30 days

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.

CVSS: 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-20
Known exploited: Added to CISA KEV Dec 17, 2025; federal remediation due Dec 24, 2025Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
EPSS (exploitation in the next 30 days): 32.39% (percentile 98)
Assigned by: cisco
NVD analysis: Analyzed
Record last updated: Oct 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Cisco Cisco Secure Email cisco:secure_email (from the name)	14.0.0-698; 13.5.1-277; 13.0.0-392; 14.2.0-620; 13.0.5-007; 13.5.4-038; 14.2.1-020; 14.3.0-032; and 10 more ranges	CNA record
Cisco Cisco Secure Email and Web Manager cisco:secure_email_and_web_manager (from the name)	13.6.2-023; 13.6.2-078; 13.0.0-249; 13.0.0-277; 13.8.1-052; 13.8.1-068; 13.8.1-074; 14.0.0-404; and 18 more ranges	CNA record
cisco asyncos cisco:asyncos	before 15.0.5-016; from 15.5 before 15.5.4-012; from 16.0 before 16.0.4-016; before 15.0.2-007; from 15.5 before 15.5.4-007; from 16.0 before 16.0.4-010	NVD

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4vendor-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-20393us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.