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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00373.

Exploitation none

Automatable yes

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Cisco Cisco Secure Email unknown
Version Status Constraints
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 affected —
15.5.2-018 affected —
16.0.0-050 affected —
15.0.3-002 affected —
16.0.0-054 affected —
15.5.3-022 affected —
16.0.1-017 affected —
15.5.4-012 affected —
16.0.4-016 affected —
15.0.5-016 affected —
16.0.2-112 affected —
16.0.3-044 affected —

No data.

No data.

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No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-esa-dfCrfXkm cve-icon cve-icon
History

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
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.
Title Cisco Secure Email Gateway Security Hardening Release
Weaknesses CWE-664
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-09-15T03:56:07.357Z

Reserved: 2025-10-08T11:59:15.414Z

Link: CVE-2026-20353

cve-icon Vulnrichment

Updated: 2026-09-14T16:34:32.087Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-14T17:17:43.000

Modified: 2026-09-15T04:18:02.940

Link: CVE-2026-20353

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T13:15:18Z

Weaknesses