Live › vulnerability › CVE-2026-20043
Go to dashboardSnort 3, the intrusion-prevention engine in Cisco Secure FTD, IOS XE UTD, Cyber Vision, Meraki MX, CDFW and CSA, has out-of-bounds write bugs (CWE-787) that Cisco found in internal testing. The worst scores CVSS 9.0: network-reachable, no auth, high complexity. Cisco says products are affected regardless of configuration, has no workaround, and knows of no exploitation. The exact traffic that triggers the bugs is not published.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| Snort 3 | vendor | 3.x < 3.12.4.0 | 3.12.4.0 |
| Cisco Secure Firewall Threat Defense (FTD) | vendor | <= 7.0 (before 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 | 7.0.10, 7.2.12, 7.4.8, 7.6.6, 7.7.13, 10.0.2, 10.1.0 |
| Cisco Cyber Vision | vendor | < 5.6.0 | 5.6.0 |
| Cisco IOS XE UTD | vendor | 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 | 17.12.8, 17.15.6, 17.18.5, 26.1.2, 26.2.1 |
snort -V; anything older than 3.12.4.0 is affected (Snort 2 is not)show versionshow version and the secapp-utd package versionUpgrade Snort 3 to 3.12.4.0 or later; for Cisco products, move to the fixed releases: FTD 7.0.10, 7.2.12, 7.4.8, 7.6.6, 7.7.13, 10.0.2 or 10.1.0; Cyber Vision 5.6.0; IOS XE UTD 17.12.8, 17.15.6, 17.18.5, 26.1.2 or 26.2.1.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
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.
This page as .md · .json · in your agent: get_signal("CVE-2026-20043")
NVD data is provided by NIST and is public domain · EPSS scores by FIRST, used with attribution. Posts quoted belong to their authors.