What it is
CVE-2026-76418 is an unauthenticated vulnerability affecting Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall.... A vulnerability in the Remote Access SSL VPN service of Cisco...
Vulnerability report
Exploitation attempts observed in the wild
High confidence
Not in CISA KEV
CVE-2026-76418
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software Denial of Service
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · 9.16.1
- Severity
- CVSS 8.6 · High
- Confidence
- High
- Exploit status
- Exploitation attempts observed in the wild
- EPSS
- —
- First observed
- —
- Last observed
- —
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Have exploitation attempts been observed?
Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Also reported by third-party sources. Confidence is high.
Who is affected?
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software Denial of Service
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.
Vendor
Product
Affected
Status
Cisco
Affected
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
Affected
Cisco
Affected
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
Affected
- Published
- 28 Oct 2026
- Exploitation Attempts Reported
- 28 Oct 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
edge
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-76418
- cisco-sa-asaftd-tunnel-dos-s6mgkb75 sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...
Exploitation evidence
Evidence of exploitation attempts
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploitation attempts observed in the wild
Cisco PSIRT CSAF
A trusted third party reported exploitation attempts.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| Cisco PSIRT CSAF First | 2026-10-28 19:44 UTC |
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Risk and context
Severity, weaknesses, and research context
CVSS v3.1
8.6
High
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS
—
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
Recent mention · Cisco Security Advisory
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel Denial of Service Vulnerability
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,...
Read full advisoryAll Mentions
Recent mention · Cisco Security Advisory
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Tunnel Denial of Service VulnerabilityCisco Security Advisory · 28 Oct 2026
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...
Timeline
From disclosure to observed exploitation attempts
-
20:05 UTC
CVE published
Vulnerability disclosed publicly
-
19:44 UTC
Added to Previdian KEV Feed
High-confidence, third-party report of exploitation attempts
-
12:02 UTC
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2026-76418
Sample API response{
"cve_id": "CVE-2026-76418",
"confidence": "High",
"cvss_score": 8.6,
"cvss_estimated": false,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}