CVE-2026-20065: cisco cisco secure firewall threat defense (ftd) software Improper Locking
Vulnerability summary
CVE-2026-20065 is a medium (CVSS 5.8) Improper Locking vulnerability in cisco cisco secure firewall threat defense (ftd) software. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.4% of scored vulnerabilities.
Timeline
- 04-03-2026PublishedVulnerability first disclosed.
- 04-03-2026Last modifiedVulnerability information updated.
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 an error in the binder module initialization logic of the Snort Detection Engine. An attacker could exploit this vulnerability by sending certain packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST5.8MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
30%
Versus all other CVEs
30-day change
+0.01 pp
From 0.37% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco5 products
- cisco secure firewall threat defense (ftd) software7.0.0 | 7.0.0.1 | 7.0.1 | 7.1.0 | 7.0.1.1 | 7.1.0.1 | 7.0.2 | 7.2.0 | 7.0.2.1 | 7.0.3 | 7.1.0.2 | 7.2.0.1 | 7.0.4 | 7.2.1 | 7.0.5 | 7.3.0 | 7.2.2 | 7.2.3 | 7.3.1 | 7.1.0.3 | 7.2.4 | 7.0.6 | 7.2.5 | 7.2.4.1 | 7.3.1.1 | 7.4.0 | 7.0.6.1 | 7.2.5.1 | 7.4.1 | 7.2.6 | 7.0.6.2 | 7.4.1.1 | 7.2.7 | 7.2.5.2 | 7.3.1.2 | 7.2.8 | 7.6.0 | 7.4.2 | 7.2.8.1 | 7.0.6.3 | 7.4.2.1 | 7.2.9 | 7.0.7 | 7.4.2.2 | 7.2.10 | 7.4.2.3 | 7.0.8 | 7.0.8.1 | 7.4.2.4 | 7.2.10.2
- cisco utd snort ips engine software17.3.1a | 17.2.1r | 17.3.2 | 17.4.1a | 17.5.1 | 17.3.3 | 17.5.1a | 17.3.4 | 17.3.4a | 17.4.2 | 17.4.1b | 17.6.1a | 17.7.1a | 17.6.2 | 17.8.1a | 17.3.5 | 17.6.3 | 17.6.3a | 17.7.2 | 17.9.1a | 17.6.4 | 17.10.1a | 17.3.6 | 17.3.7 | 17.9.2a | 17.6.5 | 17.11.1a | 17.9.3a | 17.12.1a | 17.9.4 | 17.6.6 | 17.3.8 | 17.3.8a | 17.6.6a | 17.9.4a | 17.12.2 | 17.13.1a | 17.9.5a | 17.12.3 | 17.6.7 | 17.14.1a | 17.12.4 | 17.12.3a | 17.15.1a | 17.6.8 | 17.9.6 | 17.6.8a | 17.16.1a | 17.9.5e | 17.12.4a | 17.15.2c | 17.9.5f | 17.12.4b | 17.15.2a | 17.12.5 | 17.17.1 | 17.12.5a | 17.9.7a | 17.15.3a | 17.15.3 | 17.12.5b | 17.12.5c | 17.15.4 | 17.9.7b | 17.18.1 | 17.18.1a | 17.12.6 | 17.9.8 | 17.15.4c | 17.12.5d | 17.18.2
- secure_firewall_threat_defense7.0.0 | 7.0.0.1 | 7.0.1 | 7.0.1.1 | 7.0.2 | 7.0.2.1 | 7.0.3 | 7.0.4 | 7.0.5 | 7.0.6 | 7.0.6.1 | 7.0.6.2 | 7.0.6.3 | 7.0.7 | 7.0.8 | 7.0.8.1 | 7.1.0 | 7.1.0.1 | 7.1.0.2 | 7.1.0.3 | 7.2.0 | 7.2.0.1 | 7.2.1 | 7.2.2 | 7.2.3 | 7.2.4 | 7.2.4.1 | 7.2.5 | 7.2.5.1 | 7.2.5.2 | 7.2.6 | 7.2.7 | 7.2.8 | 7.2.8.1 | 7.2.9 | 7.2.10 | 7.2.10.2 | 7.3.0 | 7.3.1 | 7.3.1.1 | 7.3.1.2 | 7.4.0 | 7.4.1 | 7.4.1.1 | 7.4.2 | 7.4.2.1 | 7.4.2.2 | 7.4.2.3 | 7.4.2.4 | 7.6.0
- snort≥ 3.0.0-233, < 3.6.3.0
- unified_threat_defense_snort_intrusion_prevention_system_engine17.2.1r | 17.3.1a | 17.3.2 | 17.3.3 | 17.3.4 | 17.3.4a | 17.3.5 | 17.3.6 | 17.3.7 | 17.3.8 | 17.3.8a | 17.4.1a | 17.4.1b | 17.4.2 | 17.5.1 | 17.5.1a | 17.6.1a | 17.6.2 | 17.6.3 | 17.6.3a | 17.6.4 | 17.6.5 | 17.6.6 | 17.6.6a | 17.6.7 | 17.6.8 | 17.6.8a | 17.7.1a | 17.7.2 | 17.8.1a | 17.9.1a | 17.9.2a | 17.9.3a | 17.9.4 | 17.9.4a | 17.9.5a | 17.9.5e | 17.9.5f | 17.9.6 | 17.9.7a | 17.9.7b | 17.9.8 | 17.10.1a | 17.11.1a | 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
1 vendor · 5 products
References
1 links- sec.cloudapps.cisco.com/security/…Vendor Advisory