CVE-2026-76443: CVE-2026-76443: As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco…

CVE-2026-76443 at a glance

CVE-2026-76443 is a critical-severity vulnerability in As, with a CVSS 3.1 base score of 9.8. NVD published it on 2026-09-14 and classifies the weakness as CWE-707. Public exploit code: 1 Metasploit module, with the earliest exploit evidence dated 2026-09-14. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 2.35% (percentile 83.7, scored 2026-11-03). NVD does not list a fixed version, so the vendor advisory is the reference for the fix. Its CVERadar threat level is 60/100.

What it is

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.

Exploitation evidence

First exploit evidence seen: 2026-09-14 (earliest date across the sources below).

Exploited in the wild

No source on this site lists in-the-wild exploitation yet (CISA KEV, VulnCheck KEV).

Public exploit code

Metasploit

• Metasploit module exploit/unix/smtp/cisco_secure_email_gateway_smime_sqli_rce: Cisco Secure Email Gateway S/MIME SQL Injection RCE (disclosure 2026-09-14)

Sources: Rapid7 Metasploit Framework module metadata.

Patches, mitigations and detection

Fixed versions

NVD does not list a fixed version for this CVE. Use the vendor advisory below.

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

No vendor-tagged reference yet; see the full reference list.

Detection Generic guidance

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.

Keeping As patched is easier with someone assigned to it; LayerLogix manages firewalls for businesses that need that help.