Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability
- Severity
- Critical9.9CVSS 3.1, Critical
- EPSS
- 71%
- Published
- 25 Sept 2025
- Updated
- 11 Aug 2026
Description
Title, description and vendor guidance are quoted from the source records.
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device.
Weakness: CWE-120
Known exploited
Added to CISA KEV on 25 Sept 2025
Federal remediation due date: 26 Sept 2025
Required action: The KEV due date refers to the deadline by which FCEB agencies are expected to review and begin implementing the guidance outlined in Emergency Directive (ED) 25-03 (URL listed below in Notes). Agencies must follow the mitigation steps provided by CISA (URL listed below in Notes) and vendor’s instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.
Exploit prediction
71% probability of exploitation in the next 30 days (percentile 99%).
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected products
Patcharo shows this vulnerability for information but does not match versions for this product yet.
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · 9.8.1, 9.8.1.5, 9.8.1.7, 9.8.2, 9.8.2.8, 9.8.2.14, 9.8.2.15, 9.8.2.17, 9.8.2.20, 9.8.2.24, 9.8.2.26, 9.8.2.28 and 194 more
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software · 6.2.3, 6.2.3.1, 6.2.3.2, 6.2.3.3, 6.2.3.4, 6.2.3.5, 6.2.3.6, 6.2.3.7, 6.2.3.8, 6.2.3.10, 6.2.3.11, 6.2.3.9 and 82 more
References
Provenance
Every fact on this page comes from the sources below. Nothing is written by an AI.
- Cisco (CVE record)
- Cisco (CVE record) · 27 Sept 2026, 23:46 UTC · Parser patcharo-cve5/1.1.0
- CISA Known Exploited Vulnerabilities
- CISA Known Exploited Vulnerabilities · 27 Sept 2026, 23:42 UTC · Parser patcharo-kev/1.0.0
- NVD
- NVD · 27 Sept 2026, 23:44 UTC · Parser patcharo-nvd/1.0.0
- FIRST EPSS
- FIRST EPSS · 27 Sept 2026, 23:46 UTC · Parser patcharo-epss/1.0.0
Last verified: 28 Sept 2026, 02:31 UTC