---
id: "CVE-2026-76461"
kind: "vulnerability"
aliases: ["CVE-2026-76461"]
title: "A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Cisco Secure Email Gateway", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "cisco asyncos", "fixed": ["15.5.5-014"], "affected": "< 15.5.5-014", "ecosystem": "vendor"}, {"name": "cisco asyncos", "fixed": ["16.0.4-302"], "affected": ">= 16.0, < 16.0.4-302", "ecosystem": "vendor"}, {"name": "cisco asyncos", "fixed": ["16.5.0-780"], "affected": ">= 16.5, < 16.5.0-780", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["asyncos", "cisco", "email-infrastructure", "exploited", "secure-email-gateway", "vendor"]
not_affected_if: ["not-using-cisco-seg"]
published_at: "2026-09-14T00:00:00+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T23:44:52+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-76461", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-76461", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# A vulnerability in the email parsing of Cisco AsyncOS Software for Cisco Secure Email Gateway could allow an…

Cisco Secure Email Gateway's AsyncOS software has a SQL injection flaw that an unauthenticated remote attacker can use to run arbitrary commands as root on the underlying OS. CISA lists it as actively exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Cisco Secure Email Gateway affected ? fixed ?
- vendor:cisco asyncos affected < 15.5.5-014 fixed 15.5.5-014
- vendor:cisco asyncos affected >= 16.0, < 16.0.4-302 fixed 16.0.4-302
- vendor:cisco asyncos affected >= 16.5, < 16.5.0-780 fixed 16.5.0-780

## How to check

Confirm whether you run Cisco Secure Email Gateway (AsyncOS) and which build it is on; the sources do not give a check command or file.
Check the Cisco security advisory for affected and fixed versions (not provided in the sources).

## Fix

Apply the Cisco vendor mitigation or patch per CISA BOD 26-04 guidance; the sources do not name a fixed version. If no mitigation is available, discontinue use of the product as CISA directs.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-76461
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-76461

## From the sources

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 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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_