CVE-2026-20052
mediumpriority · track · 0EPSS 0.004 · 38 %ileDEEUNLUSEPSS · scored 2026-10-27
A vulnerability in the memory management handling for the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a logic error in memory management when a device is performing Snort 3 SSL packet inspection. An attacker could exploit this vulnerability by sending crafted SSL packets through an established connection to be parsed by the Snort 3 Detection Engine. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.0 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Secure Firewall 3100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Secure Firewall 3100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.1.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Secure Firewall 3100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Secure Firewall 3100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.4.2.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Secure Firewall 1200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Secure Firewall 3100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Secure Firewall 4200 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com - FixedCisco Secure Firewall Threat Defense (FTD) Software 7.6.0 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (71)
Products and version ranges known to be affected.
- Cisco Secure Firewall Threat Defenseall versionscert_bundDEcpe:/a:cisco:secure_firewall_threat_defense:-
advisories (3)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0077Kwetsbaarheden verholpen in Cisco Secure Firewall systemenNL2026-03-05csaf · ncsc_nlNL
Cisco heeft meerdere kwetsbaarheden verholpen in Cisco Secure Firewall (inclusief ASA en FTD software).
- WID-SEC-W-2026-0605Cisco Secure Firewall Threat Defense: Mehrere SchwachstellenDeutsch2026-03-04csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Cisco Secure Firewall Threat Defense ausnutzen, um einen Denial of Service Angriff durchzuführen, beliebigen Code mit Root-Rechten auszuführen und Sicherheitsmaßnahmen zu umgehen.
- cisco-sa-ftd-snort3ssl-FBEKYXpHCisco Secure Firewall Threat Defense Software Snort 3 SSL Memory Management Denial of Service Vulnerability2026-03-04csaf · cisco_csafUS
A vulnerability in the memory management handling for the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a logic error in memory management when a device is performing Snort 3 SSL packet inspection. An attacker could exploit this vulnerability by sending crafted SSL packets through an established connection to be parsed by the Snort 3 Detection Engine. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the March 2026 release of the Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2026 Semiannual Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75736"].
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (4)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2026-20052cnnvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3ssl-FBEKYXpHcnnvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3ssl-FBEKYXpHenisa_euvd
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3ssl-FBEKYXpHVendor Advisorynvd
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