← Back to CVE List
CVE-2026-20248NVD
Vulnerability Summary
A vulnerability in the DNS over TCP implementation of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the TCP DNS response handler to unexpectedly restart, causing the device to reload.
This vulnerability is due to a logic error when parsing a DNS query and tracking the size of the incoming buffers. An attacker could exploit this vulnerability by formatting a crafted reply to a DNS query sent from the targeted device. A successful exploit could allow the attacker to cause the device to reload, causing a denial of service (DoS) condition.
Note: The attacker must be able to respond to DNS queries from the device, either by controlling the DNS service or through a machine-in-the-middle attack.
This vulnerability is due to a logic error when parsing a DNS query and tracking the size of the incoming buffers. An attacker could exploit this vulnerability by formatting a crafted reply to a DNS query sent from the targeted device. A successful exploit could allow the attacker to cause the device to reload, causing a denial of service (DoS) condition.
Note: The attacker must be able to respond to DNS queries from the device, either by controlling the DNS service or through a machine-in-the-middle attack.
CVSS v3.1 Base Metrics — Score 6.8 (MEDIUM)
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Affected & Patched Versions
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.1.28
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2.7
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2.11
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2.13
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.2.14
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3.14
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3.15
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.1.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.2
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3.19
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.3.23
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.2.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.2.7
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.9
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.2.8
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.14
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.18
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.9
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3.39
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.19
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.12
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3.46
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.27
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.18
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3.53
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3.55
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.38
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.39
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.3.56
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.42
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.22
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.1.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.24
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.48
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.8
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.2
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.27
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.55
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.22
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.2.10
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.57
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.28
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.24
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.2.21
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.61
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.31
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.29
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.2.22
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.62
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.34
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.67
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.70
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.40
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.1.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.71
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.4
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.47
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.7
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.37
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.76
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.9
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.38
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.50
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.1.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.10
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.1.2
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.52
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.13
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.1.6
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.53
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.82
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.16
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.19.1.42
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.57
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.84
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.3.20
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.4
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.7
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.9
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.13
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.7
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.13
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.66
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.10
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.19
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.85
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.14
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.67
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.24.1
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.68
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.22
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.14
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.20
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.71
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.19
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.26
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.89
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.2.32
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.76
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.3
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.24.1.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.22
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.24.1.9
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.28
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.22.3.5
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.16.4.92
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.135
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.195
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.30
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.24.1.155
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.23.1.32
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.24.1.11
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.34
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.18.4.82
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software >= 9.20.4.235
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.0.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.1.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.2.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.0.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.4
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.5
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.3.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.3.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.4
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.6
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.5
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.4.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.3.1.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.6.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.5.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.6
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.6.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.1.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.7
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.5.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.3.1.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.8
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.6.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.8.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.6.3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.2.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.9
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.7
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.7.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.2.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.10
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.6.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.2.3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.8
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.6.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.7.10
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.7.11
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.8.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.6.2.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.7.10.1
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.2.4
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.10.2
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.6.4
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 10.0.0
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.4
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.0.9
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.2.11
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software >= 7.4.7
Not provided by cveorg for this CVE.