CVE-2026-20250 Cisco Secure Firewall ASA & FTD - Denial of Service

Cisco Secure Firewall ASA and FTD Software for 3100 and 4200 Series contains a denial of service vulnerability caused by improper resource management in DTLS message handling, letting unauthenticated remote attackers cause device reloads, exploit requires crafted DTLS traffic.

CVSS base score 8.6 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.55% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
16 September 2026
Updated
15 October 2026
Weakness
CWE-772

Vendor fix

Update to the latest available version that addresses DTLS message handling.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

← All CVEs