10

CVE-2025-20393: Cisco Multiple Products Improper Input Validation Vulnerability

CVSS: 10.0v3.1CriticalKEVAnalyzed
Published 17-12-2025Last modified 07-10-2026

Vulnerability summary

CVE-2025-20393 is a critical (CVSS 10.0) Improper Input Validation vulnerability in Cisco Multiple Products. It is known to be exploited: CISA lists it, first on 17-12-2025. EPSS estimates a 32.39% chance of exploitation in the next 30 days, higher than 98.3% of scored vulnerabilities.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
10.0/10
010
Critical · v3.1 (CVE.org)
EPSS score
32.39%
0%100%
High · +2.52 pp in 30 days
KEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 17-12-2025
    PublishedVulnerability first disclosed.
  2. 17-12-2025
    Added to CISA KEVCisco Multiple Products Improper Input Validation Vulnerability
  3. 24-12-2025
    CISA remediation dueApply mitigations per vendor instructions.
  4. 07-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

32.39%

Chance of exploitation in the next 30 days

Percentile

98%

Versus all other CVEs

30-day change

+2.52 pp

From 29.88% on 19-09-2026

19-09-202619-10-2026
EPSS score
32.39%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
17-12-2025
Federal due date
24-12-2025

CISA 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. nvd.nist.gov/vuln/detail/CVE-2025-20393

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco3 products
  • asyncos< 15.0.5-016 | ≥ 15.5, < 15.5.4-012 | ≥ 16.0, < 16.0.4-016 | < 15.0.2-007 | ≥ 15.5, < 15.5.4-007 | ≥ 16.0, < 16.0.4-010
  • cisco secure email14.0.0-698 | 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 | 15.0.0-104 | 15.0.1-030 | 15.5.0-048 | 15.5.1-055 | 15.5.2-018 | 16.0.0-050 | 15.0.3-002 | 16.0.0-054 | 15.5.3-022 | 16.0.1-017
  • cisco secure email and web manager13.6.2-023 | 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 | 12.8.1-002 | 14.1.0-227 | 13.6.1-201 | 14.2.0-203 | 14.2.0-212 | 12.8.1-021 | 13.8.1-108 | 14.2.0-224 | 14.3.0-120 | 15.0.0-334 | 15.5.1-024 | 15.5.1-029 | 15.5.2-005 | 16.0.0-195 | 15.5.3-017 | 16.0.1-010 | 15.0.1-035 | 16.0.2-088

1 vendor · 3 products

References

2 links