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CVE-2026-20353: Improper Control of a Resource Through its Lifetime in Cisco Cisco Secure Email

0
Critical
VulnerabilityCVE-2026-20353cvecve-2026-20353
Published: 09/14/2026 (09/14/2026, 16:08:50 UTC)
Source: CVE Database V5
Vendor/Project: Cisco
Product: Cisco Secure Email

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20353 are related to issues with improper control of a resource through its lifetime that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-664.

CVSS v3.1

Score 9.8critical

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected software

Cisco

Cisco Secure Email

Affected versions
=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=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=15.5.4-012=16.0.4-016=15.0.5-016=16.0.2-112=16.0.3-044
GitHub Actionsmore threats →ai
cisco/cisco-secure-email
pkg:github/cisco/cisco-secure-email
Affected versions
=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=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=15.5.4-012=16.0.4-016=15.0.5-016=16.0.2-112=16.0.3-044

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/14/2026, 16:32:18 UTC

Technical Analysis

CVE-2026-20353 concerns improper control of a resource through its lifetime in Cisco Secure Email products. The vulnerability was discovered during Cisco's internal security review and is classified under CWE-664. It affects multiple explicit versions of Cisco Secure Email, with a critical CVSS 3.1 score of 9.8, reflecting network attack vector, low attack complexity, no privileges or user interaction required, and full impact on confidentiality, integrity, and availability. Cisco has released software hardening updates to address this issue.

Potential Impact

Successful exploitation of this vulnerability could allow an unauthenticated attacker to fully compromise the confidentiality, integrity, and availability of the affected Cisco Secure Email systems. This could lead to unauthorized access, data manipulation, or denial of service. The critical CVSS score reflects the severe potential impact.

Mitigation Recommendations

Cisco has released software hardening updates that address this vulnerability. Users should apply the official patches corresponding to their affected versions of Cisco Secure Email. Since this is not a cloud service, remediation requires manual patching. There are no known exploits in the wild at this time.

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Technical Details

Data Version
5.2
Assigner Short Name
cisco
Date Reserved
2025-10-08T11:59:15.414Z
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6aa81e7d55bf5e2cf54cc388

Added to database: 09/14/2026, 16:19:09 UTC

Last enriched: 09/14/2026, 16:32:18 UTC

Last updated: 09/15/2026, 04:02:03 UTC

Views: 12

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