CVE-2026-20050
Cisco Secure Firewall Threat Defense Decryption Policy Denial of Service Vulnerability
Description
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.
Weakness: CWE-404
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
Vendor advisory
Cisco Secure Firewall Threat Defense Software SSL Decryption Policy Denial of Service Vulnerability
Cisco’s rating: Medium (advisory CVSS 6.8) · Published Mar 4, 2026
Bug ID: CSCwq84949
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from