As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco owned Open Source Snort 3
Source GCVE Database
Not known to be exploited · CVSS 9.0 Critical.
Data as of 7 Nov 2026, 19:35 UTC
Thin evidence
One scorer or none| CNA (cisco) | CVSS 3.1 | 9.0 |
|---|
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CiscoCisco Cyber Vision | Affected
| Fixed in– |
| CiscoCisco Open Source Snort3 | Affected
| Fixed in– |
| CiscoCisco Secure Firewall Threat Defense (FTD) Software | Affected
| Fixed in– |
| CiscoCisco UTD SNORT IPS Engine Software | Affected
| Fixed in– |
AI-suggested
Cisco has conducted an internal security review and released software hardening updates to address these vulnerabilities. However, no explicit patch or fixed version information is provided in the available data. Users should consult Cisco's official advisories and update to the latest hardened releases once available.
Description
CVE-2026-20043 is a critical vulnerability in Cisco-owned Open Source Snort 3 involving out-of-bounds write issues (CWE-787). Cisco's internal security review identified these flaws, leading to software hardening releases. The vulnerability has a high CVSS score of 9.0, indicating severe impact on confidentiality, integrity, and availability. No specific affected versions or patch links are provided in the data. There is no indication of known exploits in the wild.