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    Cisco Advance Notification for Publication of October 21, 2026, Security Advisories

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    On October 21, 2026, the Cisco Product Security Incident Response Team (PSIRT) published the following advisories. To remediate the vulnerabilities that were disclosed on October 21, 2026, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories. For more information about changes in Cisco PSIRT vulnerability disclosure, see Strengthening the Foundation: A Predictable, Customer-Focused Response to AI-Accelerated Vulnerability Discovery . Snort 3 Cisco Security Advisory CVE ID Security Impact Rating CVSS Base Score Multiple Cisco Products Snort 3 Security Hardening Release: October 2026 CVE-2026-20043 CVE-2026-20236 CVE-2026-20291 CVE-2026-20356 Critical 9.0 Open Source Snort 3 Control Channel Socket Arbitrary Command Execution Vulnerability CVE-2026-76524 High 7.8 Multiple Cisco Products Snort 3 Denial of Service Vulnerabilities CVE-2026-76489 CVE-2026-20019 CVE-2026-20179 CVE-2026-20197 Medium 5.8 Multiple Cisco Products Snort 3 Generic Routing Encapsulation Denial of Service Vulnerability CVE-2026-20221 Medium 5.8 Multiple Cisco Products Snort 3 SMTP MIME Denial of Service Vulnerability CVE-2026-20011 Medium 5.8 Multiple Cisco Products Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability CVE-2026-20218 Medium 5.8 Multiple Cisco Products Snort 3 Denial of Service Vulnerability CVE-2026-76445 Medium 5.3 Cisco Expressway and Unified Communications Products Cisco Security Advisory CVE ID Security I <br/>Security Impact Rating: Informational

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    Source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-notice-QGwHnJ6k?vs_f=Cisco%20Security%20Advisory%26vs_cat=Security%20Intelligence%26vs_type=RSS%26vs_p=Cisco%20Advance%20Notification%20for%20Publication%20of%20October%2021,%202026,%20Security%20Advisories%26vs_k=1

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