CVE-2026-20043CWE-787

CVE-2026-20043

Critical · published October 21, 2026

CVSS v3.1
9.0
EPSS
0%
Percentile
17.3
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00264 · 17.3th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-10-21T21:18Z
References (1)
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-snort3-ybgmhTQe · [email protected]
EPSS history
Timeline
  • 23 OCT 03:56Z
    EPSS moved — → 0%
    epss
  • 21 OCT 16:12Z
    Multiple Cisco Products Snort 3 Software Hardening Release: October 2026
    cvelistv5
  • 21 OCT 16:12Z
    Multiple Cisco Products Snort 3 Software Hardening Release: October 2026
    cvelistv5