Double Free in Cisco Secure Firewall Threat Defense (Ftd) Software
CVE-2026-20026
Multiple Cisco products are affected by a vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer use-after-free read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to unexpectedly restart the Snort 3 Detection Engine, which could cause a denial of service (DoS).
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.007 (49.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: -0.000
Affected products
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 7.0.0, 7.0.0.1, 7.0.1
- Cisco Utd Snort Ips Engine Software — versions 3.17.1S, 16.12.3, Fuji-16.9.5
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20026?
- CVE-2026-20026 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense (Ftd) Software, classified under Double Free. CVSS score: 5.8/10. Published 2026-01-07.
- How severe is CVE-2026-20026?
- Medium severity. CVSS v3 base score is 5.8 out of 10.