Cisco Advance Notification for Publication of October 21, 2026, Security Advisories
cisco-sa-notice-QGwHnJ6k
Summary
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco owned Open Source Snort 3 Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-20043 are related to issues concerning out-of-bounds writes that are grouped under the Common Weakness Enumeration (CWE) Base CWE-787.
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco-owned Open Source Snort 3 engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.
These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and to streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class - Common Weakness Enumeration (CWE) - and assigned a single Common Vulnerabilities and Exposures Identifier (CVE ID) to each CWE grouping.
Note: Cisco may publish separate security advisories that provide additional details about individual vulnerabilities that are addressed in this release.
Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.
This advisory is part of a group of advisories. For a complete list of the advisories and links to them, see Cisco Advance Notification for Publication of October 21, 2026, Security Advisories.
Products covered
Cisco Cloud-delivered Firewall (CDFW)
Cisco Cyber Vision
Cisco Meraki MX Security Appliances
Cisco Secure Access (CSA)
Cisco Secure Firewall Threat Defense (FTD) Software
Open Source Snort 3
Unified Threat Defense (UTD) on Cisco IOS XE Software
Remediation
There are no workarounds that address these vulnerabilities.
To remediate these vulnerabilities and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.
Fixed Releases
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
For information about fixed releases, see the following sections.
Open Source Snort 3
The left column lists Snort software releases, and the right column indicates whether a release was affected by the vulnerability that is described in this advisory and which release included the fix for this vulnerability.
Snort 3 Release | First Fixed Release |
|---|---|
3.x | 3.12.4.0 |
Cyber Vision
In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.
Cisco Cyber Vision Release | First Fixed Release |
|---|---|
Earlier than 5.6 | Migrate to a fixed release. |
5.6 | 5.6.0 |
CDFW and CSA
Snort 3 is integrated natively into Cisco CDFW and CSA as part of the Snort 3 intrusion prevention system (IPS) technology to inspect traffic and block threats. No customer action is required. As of October 21, 2026, all Cisco CDFW and CSA cloud instances have been automatically updated with the Snort 3 package.
Meraki MX Security Appliances
Snort is integrated natively into Cisco Meraki security appliances as part of the threat protection services that are managed automatically through the Meraki Dashboard. No customer action is required to download Meraki firmware or the Snort 3 package for Meraki devices. As of October 21, 2026, all Meraki models listed in this advisory that are online and connected to the Cisco Meraki Dashboard have been automatically updated with the Snort 3 package.
Secure FTD Software
In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.
Cisco Secure FTD Software Release | First Fixed Release |
|---|---|
7.0 and earlier | 7.0.10 |
7.2 | 7.2.12 |
7.4 | 7.4.8 |
7.6 | 7.6.6 |
7.7 | 7.7.13 |
10.0 | 10.0.2 |
10.1 | 10.1.0 |
UTD on Cisco IOS XE Software
In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.
Cisco IOS XE Software Release | First Fixed Release |
|---|---|
17.12 | 17.12.8 |
17.15 | 17.15.6 |
17.18 | 17.18.5 |
26.1 | 26.1.2 |
26.2 | 26.2.1 |
CVEs in this advisory 4
Updates
- Published by Cisco
The publication date reported by the vendor.
- Added to SecurityAlert
We collected the advisory from the official source.