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22Track

Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability

Cisco · CVE-2026-20218 CISCO-SA-SNORT3-VBA-BUFDOS-JAUFDVN9 ZDI-26-788
0 news outlets0 CERTs and agencies1 research labs

Assessment: Track

SSVC decision points: exploitation none, automatable yes, technical impact partial, deployment high.

What is it?

A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.   This vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.

Evidence

Technical advisories1Detailed write-ups from security research teams
Official warnings1National CERTs, government cyber security agencies and the vendor’s own advisories

Exploitation

  • Public proof of concept
  • Exploited in the wild
  • Listed as known exploited
CVSS
5.8
EPSS
0.4%
First seen
1 d ago
Status
confirmed

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