Heap-based buffer overflow in Cisco Firewall Threat Defense (FTD) - CVE-2026-20053
Published: March 4, 2026
Vulnerability identifier: #VU123535
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20053
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to a boundary error in the Snort 3 VBA feature. A remote attacker can send specially crafted VBA data to the Snort 3 Detection Engine, trigger a heap-based buffer overflow and perform a denial of service attack.
Affected software
Cisco Firewall Threat Defense (FTD)
How to mitigate CVE-2026-20053
Install updates from vendor's website.
Cisco Firewall Threat Defense (FTD) - addressed in versions 7.2.11, 7.4.4, 7.6.4, 7.7.11