CVE-2026-76461: Cisco Secure Email Gateway SQL Injection Vulnerability

In short

Cisco Secure Email Gateway has a weakness classified as SQL injection (CWE-89). CISA added it to its Known Exploited Vulnerabilities catalog on 2026-09-14. NVD lists CVSS 3.1 at 9.8 CRITICAL.

What it is

“Cisco AsyncOS software for Cisco Secure Email Gateway (SEG) contains a SQL injection vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system.” — CISA KEV, retrieved 2026-11-01

“A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system. This vulnerability is due to insufficient validation in the email parsing logic. An attacker could exploit this vulnerability by sending a crafted email message that contains malicious SQL statements through an affected device. A successful exploit could allow the attacker to execute arbitrary SQL statements, leading to command execution with root privileges on the underlying operating system.” — NVD, retrieved 2026-11-01

Who is affected

Cisco Secure Email Gateway. NVD lists the following versions as affected:

• Versions before 15.5.5-014
• Versions from 16.0 inclusive, before 16.0.4-302
• Versions from 16.5 inclusive, before 16.5.0-780

Exploitation status

CISA KEV added: 2026-09-14. Known ransomware campaign use: Not reported by CISA. Due date CISA set for US federal civilian agencies: 2026-09-17.

Scores

NVD CVSS 3.1: 9.8 CRITICAL; vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; source [email protected].

EPSS by FIRST: 29.54%; percentile 98.19; score date 2026-10-31. EPSS estimates the probability of exploitation in the next 30 days.

CWE: CWE-89.

Timeline

CISA required action

“Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.” — CISA KEV

What to do

• Confirm whether you run Cisco Secure Email Gateway and which version.
• Apply the vendor update or mitigation in the advisory.
• Follow CISA’s required action.
• Review the vendor guidance on signs of compromise.
• Track the fix through completion.

References

• Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-inj-2bLVGmhX
• NVD detail
• CVE.org record
• CISA KEV catalog

Sources and dates

CISA Known Exploited Vulnerabilities Catalog, version 2026.10.30; retrieved 2026-11-01. CISA KEV data: CC0 1.0. No endorsement by CISA.

NVD retrieved: 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.

EPSS scores by FIRST; score date 2026-10-31.