Firepower Threat Defense Software
CVE-2026-20050
MEDIUM
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
Lifecycle Timeline
2DescriptionCVE.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.
AnalysisAI
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.
Technical ContextAI
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
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
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Same weakness CWE-404 – Improper Resource Shutdown or Release
View allSame technique Denial Of Service
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External POC / Exploit Code
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