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CVE-2026-20043

Multiple Cisco Products Snort 3 Software Hardening Release: October 2026

Critical9.0EPSS 0.36%
Published
Updated
Reserved
Assigned by
cisco

Description

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.

Scores

CVSS scores of CVE-2026-20043, by who scored it
Scored byCVSSScoreVector
ciscoCNA (assigner)3.1Critical9.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
NVDNVD · Awaiting Analysis3.1Critical9.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS (exploitation in 30 days)
0.36% · top 70% of all CVEs (6 Nov 2026)
CISA SSVC
Exploitation: none · Automatable: no · Technical impact: total
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.0.

Weakness

Affected products

  • Cisco · Cisco Cyber Vision

    • affected 3.0.0
    • affected 3.0.2
    • affected 3.0.3
    • affected 3.0.1
    • affected 3.1.0
    • affected 3.0.4
    • affected 3.1.1
    • affected 3.1.2
    • affected 3.2.0
    • affected 3.0.5
    • affected 3.2.1
    • affected 3.0.6
    • affected 3.2.2
    • affected 3.2.3
    • affected 3.2.4
    • affected 4.0.0
    • affected 4.0.1
    • affected 4.0.2
    • affected 4.0.3
    • affected 4.1.0
    • affected 4.1.1
    • affected 4.1.2
    • affected 4.1.3
    • affected 4.1.4
    • affected 4.2.0
    • affected 4.2.1
    • affected 4.1.5
    • affected 4.2.2
    • affected 4.2.X
    • affected 4.2.3
    • affected 4.2.4
    • affected 4.2.6
    • affected 4.1.6
    • affected 4.3.0
    • affected 4.3.1
    • affected 4.3.2
    • affected 4.3.3
    • affected 4.4.0
    • affected 4.4.1
    • affected 4.4.2
    • and 25 more

  • Cisco · Cisco Open Source Snort3

    • affected 3.12.2.0
    • affected 3.1.2.0
    • affected 3.1.3.0
    • affected 3.1.4.0
    • affected 3.1.5.0
    • affected 3.1.6.0
    • affected 3.1.7.0
    • affected 3.1.8.0
    • affected 3.1.9.0
    • affected 3.1.10.0
    • affected 3.1.12.0
    • affected 3.1.13.0
    • affected 3.1.14.0
    • affected 3.1.15.0
    • affected 3.1.16.0
    • affected 3.1.17.0
    • affected 3.1.18.0
    • affected 3.1.19.0
    • affected 3.1.20.0
    • affected 3.1.21.0
    • affected 3.1.22.0
    • affected 3.1.23.0
    • affected 3.1.24.0
    • affected 3.1.25.0
    • affected 3.1.27.0
    • affected 3.1.28.0
    • affected 3.1.29.0
    • affected 3.1.30.0
    • affected 3.1.31.0
    • affected 3.1.32.0
    • affected 3.1.36.0
    • affected 3.1.38.0
    • affected 3.1.39.0
    • affected 3.1.40.0
    • affected 3.1.41.0
    • affected 3.1.42.0
    • affected 3.1.43.0
    • affected 3.1.45.0
    • affected 3.1.47.0
    • affected 3.1.48.0
    • and 65 more

  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

    • affected 7.0.0
    • affected 7.0.0.1
    • affected 7.0.1
    • affected 7.0.1.1
    • affected 7.0.2
    • affected 7.0.2.1
    • affected 7.0.3
    • affected 7.2.0.1
    • affected 7.0.4
    • affected 7.2.1
    • affected 7.0.5
    • affected 7.3.0
    • affected 7.2.2
    • affected 7.2.3
    • affected 7.3.1
    • affected 7.2.4
    • affected 7.0.6
    • affected 7.2.5
    • affected 7.2.4.1
    • affected 7.3.1.1
    • affected 7.4.0
    • affected 7.0.6.1
    • affected 7.2.5.1
    • affected 7.4.1
    • affected 7.2.6
    • affected 7.0.6.2
    • affected 7.4.1.1
    • affected 7.2.7
    • affected 7.2.5.2
    • affected 7.3.1.2
    • affected 7.2.8
    • affected 7.6.0
    • affected 7.4.2
    • affected 7.2.8.1
    • affected 7.0.6.3
    • affected 7.4.2.1
    • affected 7.2.9
    • affected 7.0.7
    • affected 7.7.0
    • affected 7.4.2.2
    • and 19 more

  • Cisco · Cisco UTD SNORT IPS Engine Software

    • affected 17.3.1a
    • affected 17.3.2
    • affected 17.4.1a
    • affected 17.5.1
    • affected 17.3.3
    • affected 17.5.1a
    • affected 17.3.4
    • affected 17.3.4a
    • affected 17.4.2
    • affected 17.4.1b
    • affected 17.6.1a
    • affected 17.7.1a
    • affected 17.6.2
    • affected 17.8.1a
    • affected 17.3.5
    • affected 17.6.3
    • affected 17.6.3a
    • affected 17.7.2
    • affected 17.9.1a
    • affected 17.6.4
    • affected 17.10.1a
    • affected 17.3.6
    • affected 17.3.7
    • affected 17.9.2a
    • affected 17.6.5
    • affected 17.11.1a
    • affected 17.9.3a
    • affected 17.12.1a
    • affected 17.9.4
    • affected 17.6.6
    • affected 17.3.8
    • affected 17.3.8a
    • affected 17.6.6a
    • affected 17.9.4a
    • affected 17.12.2
    • affected 17.13.1a
    • affected 17.9.5a
    • affected 17.12.3
    • affected 17.6.7
    • affected 17.14.1a
    • and 43 more

What to do

Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

References (1)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2026-20043 badge
[![CVE-2026-20043](https://trackcve.app/badge/CVE-2026-20043.svg)](https://trackcve.app/cve/CVE-2026-20043)

Record last updated .