Denial of service in Cisco Secure Firewall ASA and FTD SSL VPN
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
Cisco ASA Software and FTD Software are affected. Logic errors in the Remote Access SSL VPN service, when secondary authentication is configured on a tunnel group, cause a NULL pointer dereference (CWE-690). An unauthenticated remote attacker can send a crafted request when connecting to the SSL remote access VPN, reloading the device for a denial of service. CISA lists it in the Known Exploited Vulnerabilities catalog, added 2026-10-29.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
A vulnerability in the Remote Access SSL VPN service 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 device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to logic errors when secondary authentication is configured on a tunnel group. An attacker could exploit this vulnerability by sending a crafted request when connecting to the SSL remote access VPN. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Active
- 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Cisco | Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | 9.16.1; 9.16.1.28; 9.16.2; 9.16.2.3; 9.16.2.7; 9.16.2.11; 9.16.2.13; 9.16.2.14; 9.16.3.3; 9.16.3; 9.16.3.14; 9.18.1; 9.16.3.15; 9.18.1.3; 9.18.2; 9.16.3.19; 9.16.3.23; 9.18.2.5; 9.16.4; 9.18.2.7; 9.19.1; 9.16.4.9; 9.18.2.8; 9.16.4.14; 9.18.3; 9.19.1.5; 9.16.4.18; 9.19.1.9; 9.18.3.39; 9.16.4.19; 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; 9.16.4.39; 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; 9.16.4.55; 9.18.4.22; 9.20.2.10; 9.16.4.57; 9.19.1.28; 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; 9.19.1.37; 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; 9.20.3.16; 9.19.1.42; 9.18.4.57; 9.16.4.84; 9.23.1.3; 9.20.3.20; 9.22.2.4; 9.23.1.7; 9.20.4; 9.22.2.9; 9.23.1.13; 9.20.4.7; 9.22.2.13; 9.18.4.66; 9.20.4.10; 9.23.1.19; 9.16.4.85; 9.22.2.14; 9.18.4.67; 9.24.1; 9.18.4.68; 9.23.1.22; 9.20.4.14; 9.22.2.20; 9.18.4.71; 9.20.4.19; 9.23.1.26; 9.16.4.89; 9.22.2.32; 9.18.4.76; 9.22.3; 9.24.1.5; 9.20.4.22; 9.24.1.9; 9.20.4.28; 9.22.3.5; 9.16.4.92; 9.18.4.135; 9.23.1.195; 9.20.4.30; 9.24.1.155; 9.23.1.32; 9.24.1.11; 9.20.4.34; 9.18.4.82; 9.24.10; 9.18.4.90; 9.20.4.46; 9.20.4.235; 9.20.4.49; 9.22.3.26; 9.16.4.103; 9.18.4.94; 9.23.1.47; 9.24.1.26 | — | No fix listed | CNA |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.2.0; 7.0.2.1; 7.0.3; 7.2.0.1; 7.0.4; 7.2.1; 7.0.5; 7.3.0; 7.2.2; 7.2.3; 7.3.1; 7.2.4; 7.0.6; 7.2.5; 7.2.4.1; 7.3.1.1; 7.4.0; 7.0.6.1; 7.2.5.1; 7.4.1; 7.2.6; 7.0.6.2; 7.4.1.1; 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; 7.2.10; 7.6.1; 7.4.2.3; 7.0.8; 7.6.2; 7.7.10; 7.7.11; 7.0.8.1; 7.6.2.1; 7.7.10.1; 7.4.2.4; 7.2.10.2; 7.4.3; 7.6.4; 10.0.0; 7.4.4; 7.0.9; 7.2.11; 7.4.7; 7.4.8; 7.2.12; 7.6.6; 7.7.13; 10.0.2; 7.0.10; 10.1.0 | — | No fix listed | CNA |
- Cisco Secure Firewall Adaptive Security Appliance (ASA) Software VendorCisco Affected 9.16.1; 9.16.1.28; 9.16.2; 9.16.2.3; 9.16.2.7; 9.16.2.11; 9.16.2.13; 9.16.2.14; 9.16.3.3; 9.16.3; 9.16.3.14; 9.18.1; 9.16.3.15; 9.18.1.3; 9.18.2; 9.16.3.19; 9.16.3.23; 9.18.2.5; 9.16.4; 9.18.2.7; 9.19.1; 9.16.4.9; 9.18.2.8; 9.16.4.14; 9.18.3; 9.19.1.5; 9.16.4.18; 9.19.1.9; 9.18.3.39; 9.16.4.19; 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; 9.16.4.39; 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; 9.16.4.55; 9.18.4.22; 9.20.2.10; 9.16.4.57; 9.19.1.28; 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; 9.19.1.37; 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; 9.20.3.16; 9.19.1.42; 9.18.4.57; 9.16.4.84; 9.23.1.3; 9.20.3.20; 9.22.2.4; 9.23.1.7; 9.20.4; 9.22.2.9; 9.23.1.13; 9.20.4.7; 9.22.2.13; 9.18.4.66; 9.20.4.10; 9.23.1.19; 9.16.4.85; 9.22.2.14; 9.18.4.67; 9.24.1; 9.18.4.68; 9.23.1.22; 9.20.4.14; 9.22.2.20; 9.18.4.71; 9.20.4.19; 9.23.1.26; 9.16.4.89; 9.22.2.32; 9.18.4.76; 9.22.3; 9.24.1.5; 9.20.4.22; 9.24.1.9; 9.20.4.28; 9.22.3.5; 9.16.4.92; 9.18.4.135; 9.23.1.195; 9.20.4.30; 9.24.1.155; 9.23.1.32; 9.24.1.11; 9.20.4.34; 9.18.4.82; 9.24.10; 9.18.4.90; 9.20.4.46; 9.20.4.235; 9.20.4.49; 9.22.3.26; 9.16.4.103; 9.18.4.94; 9.23.1.47; 9.24.1.26 Fixed in — No fix listed CNA
- Cisco Secure Firewall Threat Defense (FTD) Software VendorCisco Affected 7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.2.0; 7.0.2.1; 7.0.3; 7.2.0.1; 7.0.4; 7.2.1; 7.0.5; 7.3.0; 7.2.2; 7.2.3; 7.3.1; 7.2.4; 7.0.6; 7.2.5; 7.2.4.1; 7.3.1.1; 7.4.0; 7.0.6.1; 7.2.5.1; 7.4.1; 7.2.6; 7.0.6.2; 7.4.1.1; 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; 7.2.10; 7.6.1; 7.4.2.3; 7.0.8; 7.6.2; 7.7.10; 7.7.11; 7.0.8.1; 7.6.2.1; 7.7.10.1; 7.4.2.4; 7.2.10.2; 7.4.3; 7.6.4; 10.0.0; 7.4.4; 7.0.9; 7.2.11; 7.4.7; 7.4.8; 7.2.12; 7.6.6; 7.7.13; 10.0.2; 7.0.10; 10.1.0 Fixed in — No fix listed CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* | before 9.16.4.104; 9.18 to before 9.18.4.96; 9.19 to before 9.20.4.50; 9.22 to before 9.22.3.200; 9.23 to before 9.23.1.48; 9.24.1 to before 9.24.1.27 | Vulnerable | Cisco |
| cpe:2.3:o:cisco:adaptive_security_appliance_software:9.24.10:*:*:*:*:*:*:* | 9.24.10 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* | before 7.0.11; 7.2.0 to before 7.2.13; 7.3.0 to before 7.4.9; 7.6.0 – 7.6.7; 7.7.0 to before 7.7.14; 10.0.0 to before 10.0.3 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:secure_firewall_threat_defense:10.1.0:*:*:*:*:*:*:* | 10.1.0 | Vulnerable | Cisco |
- cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:* Versions before 9.16.4.104; 9.18 to before 9.18.4.96; 9.19 to before 9.20.4.50; 9.22 to before 9.22.3.200; 9.23 to before 9.23.1.48; 9.24.1 to before 9.24.1.27 Vulnerable ·Cisco
- cpe:2.3:o:cisco:adaptive_security_appliance_software:9.24.10:*:*:*:*:*:*:* Versions 9.24.10 Vulnerable ·Cisco
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:* Versions before 7.0.11; 7.2.0 to before 7.2.13; 7.3.0 to before 7.4.9; 7.6.0 – 7.6.7; 7.7.0 to before 7.7.14; 10.0.0 to before 10.0.3 Vulnerable ·Cisco
- cpe:2.3:a:cisco:secure_firewall_threat_defense:10.1.0:*:*:*:*:*:*:* Versions 10.1.0 Vulnerable ·Cisco
Remediation
The sources list no fixed version for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software. The sources list no fixed version for Cisco Secure Firewall Threat Defense (FTD) Software. CISA requires U.S. federal agencies to fix it by 2026-11-01.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Timeline
- 2026-10-28 Threatist record created from CVE-2026-76418
- 2026-10-28 Alias added: GHSA-3whv-82g3-5cwx
- 2026-10-28 CISA SSVC decision points changed
- 2026-10-29 Added to CISA KEV
- 2026-10-29 CISA SSVC decision points changed
- 2026-10-29 CISA SSVC decision points changed
- 2026-10-29 Priority changed: MEDIUM → CRITICAL
- 2026-10-30 EPSS moved to the 50th–90th percentile
- 2026-10-30 CISA SSVC decision points changed
References
Advisory 1
More Cisco Adaptive Security Appliance Software vulnerabilities
- 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-2026-16533 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
- TI-2024-13286 Infinite loop in Cisco Adaptive Security Appliance Software KEVCVSS 3.1HIGH 8.6
Sources
- CVE-2026-76418 · CVE Program
- CVE-2026-76418 · NVD
- CISA Known Exploited Vulnerabilities
- FIRST EPSS
- GHSA-3whv-82g3-5cwx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences