CVE-2026-20043: Multiple Cisco Products Snort 3 Software Hardening Release: October 2026
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-04 15:41 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by cisco, published 2026-10-21).
Weakness: Out-of-bounds Write
How it can be exploited
Exploitable over the network with high attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: no. Technical impact: total.
Public exploit evidence (Exploit Observer)
Exploit Observer found 1 research write-up naming this CVE.
See all 3 references on Exploit Observer
Live scores
- EPSS
- 0.004
low predicted chance of attack - VEDAS
- 0.800
likely exploited - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| Cisco Cyber Vision | version 3.0.0 version 3.0.2 version 3.0.3 version 3.0.1 version 3.1.0 version 3.0.4 version 3.1.1 version 3.1.2 and 57 more ranges | Not stated |
| Cisco Open Source Snort3 | version 3.12.2.0 version 3.1.2.0 version 3.1.3.0 version 3.1.4.0 version 3.1.5.0 version 3.1.6.0 version 3.1.7.0 version 3.1.8.0 and 97 more ranges | Not stated |
| Cisco Secure Firewall Threat Defense (FTD) Software | version 7.0.0 version 7.0.0.1 version 7.0.1 version 7.0.1.1 version 7.0.2 version 7.0.2.1 version 7.0.3 version 7.2.0.1 and 51 more ranges | Not stated |
| Cisco UTD SNORT IPS Engine Software | version 17.3.1a version 17.3.2 version 17.4.1a version 17.5.1 version 17.3.3 version 17.5.1a version 17.3.4 version 17.3.4a and 75 more ranges | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Other references
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
Supporting partners
