CVE-2025-20393: Cisco Multiple Products Improper Input Validation Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 17 Dec 2025, the same day the CVE record was published.
- How likely is exploitation in the next 30 days?
- 32.4%
EPSS score, percentile 98.3 of all scored records
- How severe?
- 10.0 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline 24 Dec 2025. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 14.0.0-698
- 13.5.1-277
- 13.0.0-392
- 14.2.0-620
- 13.0.5-007
- 13.5.4-038
and 18 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA due date for this action: 24 December 2025.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sma-attack-N9bf4
- https://nvd.nist.gov/vuln/detail/CVE-2025-20393
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 14.0.0-698 |
| Affected | 13.5.1-277 |
| Affected | 13.0.0-392 |
| Affected | 14.2.0-620 |
| Affected | 13.0.5-007 |
| Affected | 13.5.4-038 |
| Affected | 14.2.1-020 |
| Affected | 14.3.0-032 |
| Affected | 15.0.0-104 |
| Affected | 15.0.1-030 |
| Affected | 15.5.0-048 |
| Affected | 15.5.1-055 |
Versions not listed are: unknown.
And 6 more version entries in the CVE record.
| Status | Versions |
|---|---|
| Affected | 13.6.2-023 |
| Affected | 13.6.2-078 |
| Affected | 13.0.0-249 |
| Affected | 13.0.0-277 |
| Affected | 13.8.1-052 |
| Affected | 13.8.1-068 |
| Affected | 13.8.1-074 |
| Affected | 14.0.0-404 |
| Affected | 12.8.1-002 |
| Affected | 14.1.0-227 |
| Affected | 13.6.1-201 |
| Affected | 14.2.0-203 |
Versions not listed are: unknown.
And 14 more version entries in the CVE record.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
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.
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2025-20393 to its Known Exploited Vulnerabilities (KEV) catalog on 17 Dec 2025.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 24 Dec 2025.
- The CVE record was published on 17 Dec 2025, the same day it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 10.0 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 32.4% (percentile 98.3), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable yes, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
Cisco Secure Email Gateway and Cisco Secure Email and Web Manager Remote Command Execution Vulnerability
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| 17 Dec 2025 | CVE record published |
| 17 Dec 2025 | Added to CISA KEV |
| 24 Dec 2025 | CISA due date for the required action |
| 7 Oct 2026 | CVE record last updated |
References
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