What is CVE-2025-20135?

CVE-2025-20135 is a medium-severity vulnerability in Cisco Adaptive Security Appliance (Asa) Software, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 4.3/10. Published 2025-08-14.

How severe is CVE-2025-20135?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Cisco Adaptive Security Appliance (Asa) Software

CVE-2025-20135

A vulnerability in the DHCP client functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to exhaust avail…

EPSS: 0.002 (8.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Cisco Adaptive Security Appliance (Asa) Software — versions 9.12.3, 9.8.3, 9.12.1
Cisco Firepower Threat Defense Software — versions 6.2.3.14, 6.4.0.1, 6.2.3.7

Weakness classification (CWE)

CWE-401 — Missing Release of Memory after Effective Lifetime

References

psirt@cisco.com

Frequently asked questions

What is CVE-2025-20135?: CVE-2025-20135 is a medium-severity vulnerability in Cisco Adaptive Security Appliance (Asa) Software, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 4.3/10. Published 2025-08-14.
How severe is CVE-2025-20135?: Medium severity. CVSS v3 base score is 4.3 out of 10.