Cisco FTD SSL Decrypt Do Not Decrypt DoS via TLS1.2
CVE-2026-20050 Published on March 4, 2026
Cisco Secure Firewall Threat Defense Decryption Policy Denial of Service Vulnerability
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.
Vulnerability Analysis
CVE-2026-20050 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Improper Resource Shutdown or Release
The program does not release or incorrectly releases a resource before it is made available for re-use. When a resource is created or allocated, the developer is responsible for properly releasing the resource as well as accounting for all potential paths of expiration or invalidation, such as a set period of time or revocation.
Affected Versions
Cisco Secure Firewall Threat Defense (FTD) Software:- Version 7.0.0 is affected.
- Version 7.0.0.1 is affected.
- Version 7.0.1 is affected.
- Version 7.1.0 is affected.
- Version 7.0.1.1 is affected.
- Version 7.1.0.1 is affected.
- Version 7.0.2 is affected.
- Version 7.2.0 is affected.
- Version 7.0.2.1 is affected.
- Version 7.0.3 is affected.
- Version 7.1.0.2 is affected.
- Version 7.2.0.1 is affected.
- Version 7.0.4 is affected.
- Version 7.2.1 is affected.
- Version 7.0.5 is affected.
- Version 7.3.0 is affected.
- Version 7.2.2 is affected.
- Version 7.2.3 is affected.
- Version 7.3.1 is affected.
- Version 7.1.0.3 is affected.
- Version 7.2.4 is affected.
- Version 7.0.6 is affected.
- Version 7.2.5 is affected.
- Version 7.2.4.1 is affected.
- Version 7.3.1.1 is affected.
- Version 7.4.0 is affected.
- Version 7.0.6.1 is affected.
- Version 7.2.5.1 is affected.
- Version 7.4.1 is affected.
- Version 7.2.6 is affected.
- Version 7.0.6.2 is affected.
- Version 7.4.1.1 is affected.
- Version 7.2.7 is affected.
- Version 7.2.5.2 is affected.
- Version 7.3.1.2 is affected.
- Version 7.2.8 is affected.
- Version 7.6.0 is affected.
- Version 7.4.2 is affected.
- Version 7.2.8.1 is affected.
- Version 7.0.6.3 is affected.
- Version 7.4.2.1 is affected.
- Version 7.2.9 is affected.
- Version 7.0.7 is affected.
- Version 7.7.0 is affected.
- Version 7.4.2.2 is affected.
- Version 7.2.10 is affected.
- Version 7.6.1 is affected.
- Version 7.4.2.3 is affected.
- Version 7.0.8 is affected.
- Version 7.6.2 is affected.
- Version 7.7.10 is affected.
- Version 7.0.8.1 is affected.
- Version 7.6.2.1 is affected.
- Version 7.7.10.1 is affected.
- Version 7.4.2.4 is affected.
- Version 7.2.10.2 is affected.
- Version 7.4.3 is affected.
- Version 7.0.9 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.