CVE-2026-20050 | 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.

Published: 2026-03-04 Last update: 2026-04-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-20050 is rated Low Risk (32/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20050

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.15% 0.05% -0.11%
2 2026-04-05 0.11% 0.15% +0.05%
3 2026-03-05 0.11%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20050

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.2 4.0 [email protected]

Weakness enumeration for CVE-2026-20050

Affected software / configurations for CVE-2026-20050

Vendor Product Version Raw CPE
cisco firepower_threat_defense_software >= 7.1.0, < 7.2.11 cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cisco firepower_threat_defense_software >= 7.3.0, < 7.4.4 cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cisco firepower_threat_defense_software >= 7.6.0, < 7.6.4 cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cisco firepower_threat_defense_software >= 7.7.0, < 7.7.11 cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*

References for CVE-2026-20050

cvelogic Threat Intelligence