Cisco Secure Email: Improper Control of a Resource Through its Lifetime
CVE-2026-20353 is a critical-severity improper control of a resource through its lifetime vulnerability in Cisco Secure Email from Cisco, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Secure Email versions: 14.0.0-698; 13.5.1-277; 13.0.0-392, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Cisco Secure Email you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Secure Email | 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; and 15 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of a Resource Through its Lifetime
The product does not maintain or incorrectly maintains control over a resource throughout its lifetime of creation, use, and release.
More Improper Control of a Resource Through its Lifetime vulnerabilities (CWE-664)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Cisco Secure Email
- 9.8 Critical severity
- 9.8 Critical severity
Cisco Secure Email Gateway SQL Injection Exploited
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 10.0 Critical severity
Recent Improper Control of a Resource Through its Lifetime vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.6 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
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