Firepower Threat Defense Software
CVE-2026-20050
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2021 - Security Misconfiguration
ASVS 5.0
V15 - Secure Coding and Architecture Resource release
|
| Impact | CVSS 6.8 (MEDIUM). Attack vector: Network. Complexity: High. Privileges required: None. User interaction: None. Exploitation no authentication required. Exploitable via remote/network. |
| Exploit ScenarioDerived | A remote attacker without authentication could exploit this vulnerability to cause a reload of an affected device. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Device reloads in Cisco Secure Firewall Threat Defense can be triggered by unauthenticated remote attackers sending specially crafted TLS 1.2 traffic through the SSL decryption feature, exploiting improper memory management in the Do Not Decrypt exclusion logic. The vulnerability requires specific network conditions and TLS 1.2 traffic to trigger, resulting in denial of service with no authentication required. No patch is currently available for this medium-severity issue affecting Cisco and TLS implementations.
Earlier versions of this analysis (1)
A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. [CVSS 6.8 MEDIUM]
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
Affects your stack
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Technical ContextAI · show details
Classified as CWE-404 (Improper Resource Shutdown or Release). A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to improper memory management during the inspection of TLS 1.2 encrypted traffic. An attacker could exploit this vulnerability by sending crafted TLS 1.2 encrypted traffic through an affected device. A successful e
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Severity by source
AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
Primary rating from Vendor (cisco) · only source for this CVE.
CVSS VectorVendor: cisco
DescriptionCVE.org
A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to improper memory management during the inspection of TLS 1.2 encrypted traffic. An attacker could exploit this vulnerability by sending crafted TLS 1.2 encrypted traffic through an affected device. A successful exploit could allow the attacker to cause a reload of an affected device. Note: This vulnerability only affects traffic that is encrypted by TLS 1.2. Other versions of TLS are not affected.
Executive ViewAI
CVE-2026-20050 presents notable security risk rated CVSS 6.8. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: restrict network access and enable monitoring.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)CVE.org
A vulnerability in the Remote Access VPN (RAVPN) service of Cisco Adaptive Security Appliance (ASA) Software and Cisco F
A vulnerability in the Internet Key Exchange version 2 (IKEv2) protocol for VPN termination of Cisco Adaptive Security A
Multiple Cisco products are affected by a vulnerability in the rate filtering feature of the Snort detection engine that
Unauthenticated remote attackers can trigger a denial of service against Cisco Secure Firewall ASA and FTD devices by se
Cisco Secure Firewall ASA and Secure FTD devices can be remotely rebooted by unauthenticated attackers through malformed
Denial of service in Cisco Secure Firewall ASA and FTD Remote Access SSL VPN allows unauthenticated remote attackers to
Denial of service in Cisco ASA and FTD devices processing GCM-encrypted IKEv2 IPsec traffic results from inadequate memo
Memory exhaustion in Cisco Secure Firewall ASA and FTD IKEv2 implementations allows authenticated remote attackers with
Denial of service in Cisco Secure Firewall ASA and FTD Remote Access SSL VPN functionality allows authenticated attacker
A vulnerability in the TCP/IP traffic handling function of the Snort Detection Engine of Cisco Firepower Threat Defense
A vulnerability in the TLS processing feature of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100
A vulnerability in the Cisco Adaptive Security Appliance (ASA) restore functionality that is available in Cisco ASA Soft
GitHub PoC
Exploit-DB