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IMMUNITYSEC

CVE-2026-76418

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel Denial of Service Vulnerability

8.6
HIGH
CVSS 3.1
EPSS 0.8% · 57th pctCISA KEV · Exploited in the wild
2026-10-28Updated 2026-10-30KEV 2026-10-29
CISA Known Exploited Vulnerabilities

Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV
2026-10-29
Remediation due
2026-11-01

Required action
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

CISA notes
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tunnel-dos-s6mgkb75 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-76418

Description

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.

Severity

CVSS 3.1 · CNA8.6 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
SSVC · CISA-ADP
Exploitationactive
Automatableyes
Technical impactpartial

Key Findings

as of 2026-11-01
All KEV statistics→
  • CISA added CVE-2026-76418 to the KEV catalog 1 day after its CVE record was published. The median for entries added in 2026 so far is 14 days.
  • It is one of 102 Cisco entries in the CISA KEV catalog, and one of 20 added in 2026.
  • Its current EPSS score (0.8%) is higher than that of 2% of CISA KEV entries.

Affected Products

ProductAffected versions
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
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

References

1 links

Record Details

Published
2026-10-28
Last updated
2026-10-30
Assigner (CNA)
cisco
Credited to
-

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). Alert titles and links from CISA cybersecurity alerts. This site is not affiliated with or endorsed by MITRE, NVD, CISA, or FIRST.