Cisco Security Advisoriescisco-sa-notice-QGwHnJ6k

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

34 CVEs Published Oct 21, 2026 at 4:09 PM UTC

14 advisories 34 CVEs 3 product groups

Summary

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.

Products covered

Snort 3
Cisco Expressway and Unified Communications Products
Cisco IOS XR Software and Secure Client

7 advisories

Snort 3

Multiple Cisco Products Snort 3 Security Hardening Release: October 2026

CriticalCVSS 9.0

CVE-2026-20043 CVE-2026-20236 CVE-2026-20291 CVE-2026-20356
Open Source Snort 3 Control Channel Socket Arbitrary Command Execution Vulnerability

HighCVSS 7.8

CVE-2026-76524
Multiple Cisco Products Snort 3 Denial of Service Vulnerabilities

MediumCVSS 5.8

CVE-2026-76489 CVE-2026-20019 CVE-2026-20179 CVE-2026-20197
Multiple Cisco Products Snort 3 Generic Routing Encapsulation Denial of Service Vulnerability

MediumCVSS 5.8

CVE-2026-20221
Multiple Cisco Products Snort 3 SMTP MIME Denial of Service Vulnerability

MediumCVSS 5.8

CVE-2026-20011
Multiple Cisco Products Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability

MediumCVSS 5.8

CVE-2026-20218
Multiple Cisco Products Snort 3 Denial of Service Vulnerability

MediumCVSS 5.3

CVE-2026-76445

5 advisories

Cisco Expressway and Unified Communications Products

Cisco Expressway Series Remote Code Execution Vulnerability

CriticalCVSS 9.8

CVE-2026-76466
Cisco Expressway Series Security Hardening Release: October 2026

HighCVSS 8.6

CVE-2026-76490 CVE-2026-76491 CVE-2026-76492 CVE-2026-76493 CVE-2026-76494 CVE-2026-76495 CVE-2026-76496 CVE-2026-76497
Cisco Expressway Series Information Disclosure Vulnerability

MediumCVSS 5.3

CVE-2026-76435
Cisco Unified Communications Products Security Hardening Release: October 2026

CriticalCVSS 9.8

CVE-2026-76476 CVE-2026-76473 CVE-2026-76475 CVE-2026-76477 CVE-2026-76478 CVE-2026-76479 CVE-2026-76481 CVE-2026-76474
Cisco Unified Communications Manager Improper Access Control Vulnerability

MediumCVSS 5.3

CVE-2026-76487

2 advisories

Cisco IOS XR Software and Secure Client

Cisco IOS XR Software for ASR 9000 Series Routers IPv4 Unicast Packets Denial of Service Vulnerability

HighCVSS 7.5

CVE-2026-76505
Cisco Secure Client Secure Firewall Posture Module Privilege Escalation Vulnerability

HighCVSS 5.5

CVE-2026-76462

Remediation

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.

Updates

Oct 21, 2026 at 4:09 PM UTC
Published by Cisco
The publication date reported by the vendor.
Oct 21, 2026 at 4:15 PM UTC
Added to SecurityAlert
We collected the advisory from the official source.

Source

Details collected from Cisco Security Advisories.

Vendor: Cisco
Advisory ID: cisco-sa-notice-QGwHnJ6k
Last source check: Oct 14, 2026 at 3:40 PM UTC

Official bulletin How SecurityAlert builds this record

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