CVE-2026-20248

CVE CVE-2026-20248EUVD EUVD-2026-81143Published 2026-09-16T20:17:47.000ZLast changed 2026-09-18T19:08:55.000ZCVSS 6.8

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.18.4.29; 9.20.2.21; 9.16.2.11; 9.19.1.31; 9.18.4.5; 9.20.4.19; 9.20.3.16; 9.20.4.235; 9.18.4.8; 9.20.3.4; 9.22.3; 9.16.4.48; 9.16.2; 9.23.1.19; 9.16.4.27; 9.18.4.71; 9.19.1.18; 9.18.4.57; 9.18.3.55; 9.24.1.155; 9.20.4.14; 9.19.1.27; 9.20.2.22; 9.16.4.92; 9.18.4.50; 9.18.4.24; 9.20.1.5; 9.19.1.24; 9.22.2.32; 9.22.1.1; 9.23.1.22; 9.22.1.6; 9.16.4.18; 9.24.1; 9.19.1.37; 9.22.2.20; 9.16.4.82; 9.23.1.195; 9.16.2.14; 9.24.1.9; 9.23.1.7; 9.18.1; 9.16.4.67; 9.16.3.14; 9.16.4.61; 9.20.1; 9.20.3.10; 9.16.4.57; 9.16.4.89; 9.20.4.34; 9.18.3.56; 9.18.2.5; 9.18.3.39; 9.20.3; 9.16.4.9; 9.18.2.7; 9.23.1; 9.22.1.2; 9.16.4.42; 9.16.4.62; 9.16.4.84; 9.18.4.34; 9.16.1.28; 9.16.3.19; 9.18.4.22; 9.18.4.68; 9.23.1.26; 9.23.1.32; 9.19.1.12; 9.18.3.46; 9.16.4; 9.22.2.4; 9.18.2.8; 9.16.3.15; 9.18.4.67; 9.20.4.10; 9.18.3.53; 9.18.4.66; 9.20.3.9; 9.16.2.13; 9.22.1.3; 9.19.1.28; 9.22.2.13; 9.20.4.22; 9.24.1.11; 9.16.4.55; 9.19.1.42; 9.22.3.5; 9.18.4.52; 9.22.2; 9.18.1.3; 9.20.4; 9.18.4.135; 9.19.1.5; 9.16.1; 9.16.4.71; 9.19.1; 9.16.4.19; 9.22.2.9; 9.20.3.13; 9.16.4.14; 9.22.2.14; 9.16.4.70; 9.16.4.39; 9.23.1.13; 9.18.4.53; 9.16.4.85; 9.20.4.30; 9.19.1.38; 9.16.3.23; 9.18.4.82; 9.20.3.7; 9.18.4.47; 9.20.2; 9.18.4.40; 9.18.3; 9.20.4.28; 9.16.4.38; 9.19.1.22; 9.20.2.10; 9.19.1.9; 9.23.1.3; 9.18.4.76; 9.24.1.5; 9.16.2.7; 9.20.3.20; 9.16.4.76; 9.20.4.7; 9.16.2.3; 9.16.3; 9.18.2; 9.18.4; 9.16.3.3
Cisco — Cisco Secure Firewall Threat Defense (FTD) Software 7.4.2.4; 7.4.0; 7.0.5; 7.4.7; 7.0.6.2; 7.2.10; 7.0.1; 7.6.0; 7.2.8; 7.2.1; 7.0.0; 7.0.3; 7.0.6.1; 7.6.1; 7.6.4; 7.0.2.1; 7.2.4.1; 7.4.2; 7.6.2.1; 7.4.2.2; 7.0.4; 7.0.7; 7.0.1.1; 7.7.10.1; 7.3.1.1; 7.4.2.3; 7.2.7; 7.3.1; 7.2.5; 7.3.1.2; 7.2.3; 7.4.3; 7.4.1.1; 7.2.0.1; 7.0.9; 7.0.8.1; 7.2.11; 7.0.6; 7.2.10.2; 7.6.2; 7.4.2.1; 7.7.10; 7.4.4; 7.0.8; 7.3.0; 7.2.8.1; 10.0.0; 7.2.5.1; 7.2.5.2; 7.7.0; 7.2.0; 7.2.9; 7.7.11; 7.0.2; 7.0.6.3; 7.2.4; 7.4.1; 7.0.0.1; 7.2.6; 7.2.2

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

Cisco — Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco — Secure Firewall Threat Defense (FTD) Software

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