SB20260918124 - Multiple vulnerabilities in Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
Published: September 18, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Infinite loop (CVE-ID: CVE-2026-20154)
CWE-ID: CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to improper rate limiting for syslog message 419002. A remote attacker can consume all available system resources and cause denial of service conditions.
2) Signed to Unsigned Conversion Error (CVE-ID: CVE-2026-20248)
CWE-ID: CWE-195 - Signed to Unsigned Conversion Error
CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a logic error when parsing a DNS query and tracking the size of the incoming buffers. A remote attacker can cause a denial of service condition on the target system.
3) Improper access control (CVE-ID: CVE-2026-20121)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to a logic error in populating group access control policies (ACPs) with Object Group Search (OGS) configured. A remote attacker can bypass access controls and reach devices in protected networks.
4) Improper access control (CVE-ID: CVE-2026-20120)
CWE-ID: CWE-284 - Improper Access Control
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to a logic error in populating group access control policies (ACPs) with Object Group Search (OGS) configured. A remote attacker can bypass access controls and reach devices in protected networks.
Remediation
Install update from vendor's website.
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-logging-dos-ZXXNesfN
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tcpdns-dos-p6dUnjr5
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-acl-bypass-8p6vFvw