---
title: "CVE-2026-76466: Cisco Expressway Series - Remote Code Execution"
description: "Cisco Expressway Series contains a remote code execution caused by use of persistent cookies and insufficient client certificate validation in database service, letting unauthenticated remote attackers execute arbitrary OS commands as root, exploit requires possession of persistent cookies."
url: https://panop.io/threat-heartbeat/CVE-2026-76466/
---

# CVE-2026-76466 Cisco Expressway Series - Remote Code Execution

Cisco Expressway Series contains a remote code execution caused by use of persistent cookies and insufficient client certificate validation in database service, letting unauthenticated remote attackers execute arbitrary OS commands as root, exploit requires possession of persistent cookies.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-76466)

## Details

Type

Remote Code Execution

Impact

Remote Code Execution

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

21 October 2026

Updated

22 October 2026

Weakness

[CWE-798](https://cwe.mitre.org/data/definitions/798.html)

## Vendor fix

Update to the latest Cisco Expressway Series version with security patches.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-76466](https://nvd.nist.gov/vuln/detail/CVE-2026-76466)
- [https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-vcs-static-cred-hr7EWZ8t](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-vcs-static-cred-hr7EWZ8t)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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