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TI-2026-16254 Aliases CVE-2026-20039GHSA-ch3j-whf9-3xp2

Cisco Adaptive Security Appliance and Firepower Threat Defense Software SSL VPN…

Priority MEDIUM 43CWE-244Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

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 unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to ineffective memory management of the VPN web server. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00411 35th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software9.12.3; 9.12.1; 9.12.2; 9.12.4; 9.12.3.2; 9.12.3.7; 9.12.2.5; 9.12.3.12; 9.12.1.3; 9.12.2.4; 9.12.1.2; 9.12.2.9; 9.12.3.9; 9.12.2.1; 9.12.4.2; 9.12.4.4; 9.12.4.7; 9.12.4.8; 9.12.4.10; 9.12.4.13; 9.12.4.18; 9.12.4.24; 9.16.1; 9.12.4.26; 9.16.1.28; 9.12.4.29; 9.16.2; 9.12.4.30; 9.16.2.3; 9.12.4.35; 9.16.2.7; 9.12.4.37; 9.17.1; 9.16.2.11; 9.16.2.13; 9.12.4.39; 9.12.4.38; 9.16.2.14; 9.17.1.7; 9.12.4.40; 9.16.3.3; 9.16.3; 9.16.3.14; 9.17.1.9; 9.12.4.41; 9.17.1.10; 9.18.1; 9.12.4.47; 9.16.3.15; 9.18.1.3; 9.17.1.11; 9.12.4.48; 9.18.2; 9.16.3.19; 9.17.1.13; 9.12.4.50; 9.17.1.15; 9.12.4.52; 9.16.3.23; 9.18.2.5; 9.16.4; 9.12.4.54; 9.17.1.20; 9.18.2.7; 9.19.1; 9.16.4.9; 9.12.4.55; 9.18.2.8; 9.16.4.14; 9.18.3; 9.19.1.5; 9.12.4.56; 9.17.1.30; 9.19.1.9; 9.18.3.39; 9.16.4.19; 9.12.4.58; 9.19.1.12; 9.18.3.46; 9.16.4.27; 9.19.1.18; 9.18.3.53; 9.18.3.55; 9.16.4.38; 9.17.1.33; 9.12.4.62; 9.16.4.39; 9.18.3.56; 9.20.1; 9.16.4.42; 9.19.1.22; 9.18.4; 9.20.1.5; 9.18.4.5; 9.19.1.24; 9.16.4.48; 9.18.4.8; 9.20.2; 9.19.1.27; 9.12.4.65; 9.16.4.55; 9.18.4.22; 9.20.2.10; 9.16.4.57; 9.19.1.28; 9.17.1.39; 9.12.4.67; 9.18.4.24; 9.20.2.21; 9.16.4.61; 9.19.1.31; 9.18.4.29; 9.20.2.22; 9.16.4.62; 9.18.4.34; 9.20.3; 9.16.4.67; 9.16.4.70; 9.18.4.40; 9.23.1; 9.22.1.1; 9.16.4.71; 9.20.3.4; 9.18.4.47; 9.20.3.7; 9.17.1.45; 9.19.1.37; 9.17.1.46; 9.16.4.76; 9.20.3.9; 9.19.1.38; 9.18.4.50; 9.22.1.3; 9.20.3.10; 9.22.1.2; 9.18.4.52; 9.20.3.13; 9.22.1.6; 9.18.4.53; 9.16.4.82; 9.22.2; 9.19.1.42—No fix listedCNA
CiscoCisco Secure Firewall Threat Defense (FTD) Software6.4.0.1; 6.4.0.2; 6.4.0.5; 6.4.0; 6.4.0.3; 6.4.0.4; 6.4.0.6; 6.4.0.7; 6.4.0.8; 6.4.0.9; 6.4.0.10; 6.4.0.11; 6.4.0.12; 7.0.0; 7.0.0.1; 7.0.1; 7.1.0; 6.4.0.13; 7.0.1.1; 6.4.0.14; 7.1.0.1; 7.0.2; 6.4.0.15; 7.2.0; 7.0.2.1; 7.0.3; 7.1.0.2; 7.2.0.1; 7.0.4; 7.2.1; 7.0.5; 6.4.0.16; 7.3.0; 7.2.2; 7.2.3; 7.3.1; 7.1.0.3; 7.2.4; 7.0.6; 7.2.5; 7.2.4.1; 7.3.1.1; 7.4.0; 6.4.0.17; 7.0.6.1; 7.2.5.1; 7.4.1; 7.2.6; 7.0.6.2; 7.4.1.1; 6.4.0.18; 7.2.7; 7.2.5.2; 7.3.1.2; 7.2.8; 7.6.0; 7.4.2; 7.2.8.1; 7.0.6.3; 7.4.2.1; 7.2.9; 7.0.7; 7.7.0; 7.4.2.2; 7.4.2.3; 7.0.8; 7.0.8.1; 7.4.2.4—No fix listedCNA
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Software VendorCisco Affected 9.12.3; 9.12.1; 9.12.2; 9.12.4; 9.12.3.2; 9.12.3.7; 9.12.2.5; 9.12.3.12; 9.12.1.3; 9.12.2.4; 9.12.1.2; 9.12.2.9; 9.12.3.9; 9.12.2.1; 9.12.4.2; 9.12.4.4; 9.12.4.7; 9.12.4.8; 9.12.4.10; 9.12.4.13; 9.12.4.18; 9.12.4.24; 9.16.1; 9.12.4.26; 9.16.1.28; 9.12.4.29; 9.16.2; 9.12.4.30; 9.16.2.3; 9.12.4.35; 9.16.2.7; 9.12.4.37; 9.17.1; 9.16.2.11; 9.16.2.13; 9.12.4.39; 9.12.4.38; 9.16.2.14; 9.17.1.7; 9.12.4.40; 9.16.3.3; 9.16.3; 9.16.3.14; 9.17.1.9; 9.12.4.41; 9.17.1.10; 9.18.1; 9.12.4.47; 9.16.3.15; 9.18.1.3; 9.17.1.11; 9.12.4.48; 9.18.2; 9.16.3.19; 9.17.1.13; 9.12.4.50; 9.17.1.15; 9.12.4.52; 9.16.3.23; 9.18.2.5; 9.16.4; 9.12.4.54; 9.17.1.20; 9.18.2.7; 9.19.1; 9.16.4.9; 9.12.4.55; 9.18.2.8; 9.16.4.14; 9.18.3; 9.19.1.5; 9.12.4.56; 9.17.1.30; 9.19.1.9; 9.18.3.39; 9.16.4.19; 9.12.4.58; 9.19.1.12; 9.18.3.46; 9.16.4.27; 9.19.1.18; 9.18.3.53; 9.18.3.55; 9.16.4.38; 9.17.1.33; 9.12.4.62; 9.16.4.39; 9.18.3.56; 9.20.1; 9.16.4.42; 9.19.1.22; 9.18.4; 9.20.1.5; 9.18.4.5; 9.19.1.24; 9.16.4.48; 9.18.4.8; 9.20.2; 9.19.1.27; 9.12.4.65; 9.16.4.55; 9.18.4.22; 9.20.2.10; 9.16.4.57; 9.19.1.28; 9.17.1.39; 9.12.4.67; 9.18.4.24; 9.20.2.21; 9.16.4.61; 9.19.1.31; 9.18.4.29; 9.20.2.22; 9.16.4.62; 9.18.4.34; 9.20.3; 9.16.4.67; 9.16.4.70; 9.18.4.40; 9.23.1; 9.22.1.1; 9.16.4.71; 9.20.3.4; 9.18.4.47; 9.20.3.7; 9.17.1.45; 9.19.1.37; 9.17.1.46; 9.16.4.76; 9.20.3.9; 9.19.1.38; 9.18.4.50; 9.22.1.3; 9.20.3.10; 9.22.1.2; 9.18.4.52; 9.20.3.13; 9.22.1.6; 9.18.4.53; 9.16.4.82; 9.22.2; 9.19.1.42 Fixed in — No fix listed CNA
  • Cisco Secure Firewall Threat Defense (FTD) Software VendorCisco Affected 6.4.0.1; 6.4.0.2; 6.4.0.5; 6.4.0; 6.4.0.3; 6.4.0.4; 6.4.0.6; 6.4.0.7; 6.4.0.8; 6.4.0.9; 6.4.0.10; 6.4.0.11; 6.4.0.12; 7.0.0; 7.0.0.1; 7.0.1; 7.1.0; 6.4.0.13; 7.0.1.1; 6.4.0.14; 7.1.0.1; 7.0.2; 6.4.0.15; 7.2.0; 7.0.2.1; 7.0.3; 7.1.0.2; 7.2.0.1; 7.0.4; 7.2.1; 7.0.5; 6.4.0.16; 7.3.0; 7.2.2; 7.2.3; 7.3.1; 7.1.0.3; 7.2.4; 7.0.6; 7.2.5; 7.2.4.1; 7.3.1.1; 7.4.0; 6.4.0.17; 7.0.6.1; 7.2.5.1; 7.4.1; 7.2.6; 7.0.6.2; 7.4.1.1; 6.4.0.18; 7.2.7; 7.2.5.2; 7.3.1.2; 7.2.8; 7.6.0; 7.4.2; 7.2.8.1; 7.0.6.3; 7.4.2.1; 7.2.9; 7.0.7; 7.7.0; 7.4.2.2; 7.4.2.3; 7.0.8; 7.0.8.1; 7.4.2.4 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*9.12.1 to before 9.16.4.84; 9.17.1 to before 9.18.4.57; 9.19.1 to before 9.20.3.16; 9.22.1.1 to before 9.22.2.4; 9.23.1 to before 9.23.1.3VulnerableCisco
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*6.4.0 to before 7.0.9; 7.1.0 to before 7.2.10; 7.3.0 to before 7.4.3; 7.6.0 to before 7.6.1; 7.7.0 to before 7.7.10VulnerableCisco
  • cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions 9.12.1 to before 9.16.4.84; 9.17.1 to before 9.18.4.57; 9.19.1 to before 9.20.3.16; 9.22.1.1 to before 9.22.2.4; 9.23.1 to before 9.23.1.3 Vulnerable ·Cisco
  • cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions 6.4.0 to before 7.0.9; 7.1.0 to before 7.2.10; 7.3.0 to before 7.4.3; 7.6.0 to before 7.6.1; 7.7.0 to before 7.7.10 Vulnerable ·Cisco

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-20039
  2. 2026-10-03 Alias added: GHSA-ch3j-whf9-3xp2

References

Advisory 1

  • TI-2025-14628 Buffer overflow in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.9
  • TI-2016-05454 Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on… KEVCVSS 3.1HIGH 8.8
  • TI-2023-06973 Authentication bypass in Cisco Adaptive Security Appliance Software KEVCVSS 3.1CRITICAL 9.1
  • TI-2026-82192 Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN KEVCVSS 3.1HIGH 8.6
  • TI-2026-16533 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense… KEVCVSS 3.1HIGH 8.6
  • TI-2025-14657 Missing authorization in Cisco Secure Firewall Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
See all 354 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences