CVE-2026-20005

Medium

Description

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete parsing of the SSL handshake ingress packets. An attacker could exploit this vulnerability by sending crafted SSL handshake packets. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine restarts unexpectedly.

SeverityMedium
CVSS5.8
Exploit probability—
ProductCisco Snort
PublishedMar 4, 2026
First seenMar 4, 2026
Weakness typeCWE-392CWE-392

How to fix

Update
  • cisco snort3.9.2.0 or later

Affected products

ProductAffected versionsFixed in
cisco snort3.0.0-233 ≤ v < 3.9.2.03.9.2.0
cisco cyber_vision3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.0.6, 3.1.0, 3.1.1, 3.1.2, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 3.2.4, 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7, 4.2.0, 4.2.1, 4.2.2, 4.2.3, 4.2.4, 4.2.6, 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.4.0, 4.4.1, 4.4.2, 4.4.3, 5.0.0, 5.0.1, 5.0.2, 5.1.0, 5.1.1, 5.1.2, 5.1.3, 5.2.0, 5.2.1, 5.3.0, 5.3.1, 5.3.2—
cisco secure_firewall_threat_defense7.6.0, 7.6.1, 7.6.2, 7.6.2.1, 7.7.0, 7.7.10, 7.7.10.1—
cisco unified_threat_defense_snort_intrusion_prevention_system_engine17.9.4, 17.9.5e, 17.12.1a, 17.12.2, 17.12.3, 17.12.3a, 17.12.4, 17.12.4a, 17.12.4b, 17.12.5, 17.12.5a, 17.12.5b, 17.12.5c, 17.12.5d, 17.12.6, 17.13.1a, 17.14.1a, 17.15.1a, 17.15.2a, 17.15.2c, 17.15.3, 17.15.3a, 17.15.4, 17.15.4c, 17.16.1a, 17.17.1, 17.18.1, 17.18.1a, 17.18.2—

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