CVE-2026-20353
Cisco Secure Email Gateway Security Hardening Release
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.
Weakness: CWE-664
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Secure Email Gateway | Email Security | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Secure Email
Vendor advisory
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Cisco Secure Email Gateway and Secure Email and Web Manager Security Hardening Release: September 2026
Cisco’s rating: Critical (advisory CVSS 9.8) · Published Sep 14, 2026
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from