Is CVE-2026-20052 being actively exploited?

CVE-2026-20052 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2026-20052?

CVE-2026-20052 has a CVSS 3.1 base score of 5.8 (MEDIUM).

CVE-2026-20052

MEDIUM · CVSS 5.8EPSS 0.4%EU EUVD

A vulnerability in the memory management handling for the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a logic error in memory management when a device is performing Snort 3 SSL packet inspection. An attacker could exploit this vulnerability by sending crafted SSL packets through an established connection to be parsed by the Snort 3 Detection Engine. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.

Key facts

CVSS score: 5.8 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness (CWE): CWE-788
EPSS score: 0.4% (36th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2026-9458)
Published: March 4, 2026
NVD last modified: August 20, 2026
Status: Analyzed

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-9458 in the EU Vulnerability Database. Last updated in EUVD on March 4, 2026.

View on the EU Vulnerability Database

Affected products

cisco / secure firewall threat defense
cisco / secure firewall threat defense
cisco / secure firewall threat defense
cisco / secure firewall threat defense
cisco / secure firewall threat defense
cisco / secure firewall threat defense

Certified products that may be affected

2 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Cisco Secure Firewall Threat Defense (FTD) 7.4 with Secure Firewall Management Center (FMC) 7.4 and Secure Client 5.1 - Cisco Systems, Inc. - Common Criteria NSCIB-CC-2400046-01-CR - active
Cisco Secure Firewall Threat Defense Virtual 7.4 with FMC/FMCv - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11510-2025 - active

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3ssl-FBEKYXpH(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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