CVE-2026-76443

Cisco Secure Email Gateway Security Hardening Release

Published Sep 14, 2026 CVSS 3.1 · 9.8 Critical EPSS 2.4% KEV · Not listed

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-2026-76443 are related to issues with improper neutralization that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-707.

Analysis

Technical impact

The vulnerability identified by CVE‑2026‑76443 arises from improper neutralization of input within Cisco Secure Email Gateway and Cisco Secure Email and Web Manager products. Improper neutralization can allow attackers to supply specially crafted data that bypasses the system’s expected sanitization process, potentially leading to the execution of arbitrary code or other unauthorized actions. The flaw is directly tied to CWE‑707, highlighting the risk of malicious content being interpreted as executable by the application.

Affected Systems

Products impacted are Cisco Secure Email Gateway and Cisco Secure Email and Web Manager. The advisory does not specify particular software versions, but the issue applies to all builds that have not been updated with the latest hardening release.

Risk and Exploitability

The CVSS score of 9.8 indicates a critically high severity. The EPSS score of 2% indicates a low exploitation probability, and the vulnerability is not listed in the CISA KEV catalog, suggesting that publicly known exploits have not yet been observed. Because the weakness involves improper neutralization that can be leveraged from external network traffic, the attack vector is inferred to be remote, and the vulnerability can potentially be exploited by adversaries with network access to the email gateway.

Affected Products

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	—

Cisco

Cisco Secure Email and Web Manager

unknown

Version	Status	Constraints
`13.6.2-023`	affected	—
`13.6.2-078`	affected	—
`13.0.0-249`	affected	—
`13.0.0-277`	affected	—
`13.8.1-052`	affected	—
`13.8.1-068`	affected	—
`13.8.1-074`	affected	—
`14.0.0-404`	affected	—
`12.8.1-002`	affected	—
`14.1.0-227`	affected	—
`13.6.1-201`	affected	—
`14.2.0-203`	affected	—
`14.2.0-212`	affected	—
`12.8.1-021`	affected	—
`13.8.1-108`	affected	—
`14.2.0-224`	affected	—
`14.3.0-120`	affected	—
`15.0.0-334`	affected	—
`15.5.1-024`	affected	—
`15.5.1-029`	affected	—
`15.5.2-005`	affected	—
`16.0.0-195`	affected	—
`15.5.3-017`	affected	—
`16.0.1-010`	affected	—
`15.0.1-035`	affected	—
`16.0.2-088`	affected	—
`15.5.4-007`	affected	—
`15.0.2-007`	affected	—
`16.0.4-010`	affected	—
`16.0.3-016`	affected	—

No data.

Vendor Product Versions

Cisco

Secure Email

Version	Status	Scheme	Platform
`14.0.0-698`	affected	semver	—
`13.5.1-277`	affected	semver	—
`13.0.0-392`	affected	semver	—
`14.2.0-620`	affected	semver	—
`13.0.5-007`	affected	semver	—
`13.5.4-038`	affected	semver	—
`14.2.1-020`	affected	semver	—
`14.3.0-032`	affected	semver	—
`15.0.0-104`	affected	semver	—
`15.0.1-030`	affected	semver	—
`15.5.0-048`	affected	semver	—
`15.5.1-055`	affected	semver	—
`15.5.2-018`	affected	semver	—
`16.0.0-050`	affected	semver	—
`15.0.3-002`	affected	semver	—
`16.0.0-054`	affected	semver	—
`15.5.3-022`	affected	semver	—
`16.0.1-017`	affected	semver	—
`15.5.4-012`	affected	semver	—
`16.0.4-016`	affected	semver	—
`15.0.5-016`	affected	semver	—
`16.0.2-112`	affected	semver	—
`16.0.3-044`	affected	semver	—

Cisco

Secure Email And Web Manager

Version	Status	Scheme	Platform
`13.6.2-023`	affected	semver	—
`13.6.2-078`	affected	semver	—
`13.0.0-249`	affected	semver	—
`13.0.0-277`	affected	semver	—
`13.8.1-052`	affected	semver	—
`13.8.1-068`	affected	semver	—
`13.8.1-074`	affected	semver	—
`14.0.0-404`	affected	semver	—
`12.8.1-002`	affected	semver	—
`14.1.0-227`	affected	semver	—
`13.6.1-201`	affected	semver	—
`14.2.0-203`	affected	semver	—
`14.2.0-212`	affected	semver	—
`12.8.1-021`	affected	semver	—
`13.8.1-108`	affected	semver	—
`14.2.0-224`	affected	semver	—
`14.3.0-120`	affected	semver	—
`15.0.0-334`	affected	semver	—
`15.5.1-024`	affected	semver	—
`15.5.1-029`	affected	semver	—
`15.5.2-005`	affected	semver	—
`16.0.0-195`	affected	semver	—
`15.5.3-017`	affected	semver	—
`16.0.1-010`	affected	semver	—
`15.0.1-035`	affected	semver	—
`16.0.2-088`	affected	semver	—
`15.5.4-007`	affected	semver	—
`15.0.2-007`	affected	semver	—
`16.0.4-010`	affected	semver	—
`16.0.3-016`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Install the Cisco Secure Email Gateway hardening release that addresses the improper neutralization issue, as provided by Cisco.
Restart the Cisco Secure Email Gateway and Cisco Secure Email and Web Manager services to ensure the new firmware is active.
Review and, if applicable, update any custom or third-party email handling scripts, connectors, or plugins to enforce proper input validation or neutralization practices.

Generated by OpenCVE AI on October 28, 2026 at 15:02 UTC.

Tracking

Advisories

No advisories available

Metrics

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.

Exploit prediction score: 2.4% (2.354% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact total

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-esa-dfCrfXkm
https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification

History

Sep 17, 2026 9:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco secure Email Cisco secure Email And Web Manager
Vendors & Products		Cisco Cisco secure Email Cisco secure Email And Web Manager

Sep 15, 2026 6:30 PM Added references View changes

Type	Values Removed	Values Added
References		https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification

Sep 14, 2026 9:00 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

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-2026-76443 are related to issues with improper neutralization that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-707.
Title		Cisco Secure Email Gateway Security Hardening Release
Weaknesses		CWE-707
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-esa-dfCrfXkm
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'}`