What it is
CVE-2025-20362 is an unauthenticated vulnerability affecting Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall.... Update: On November 5, 2025, Cisco became aware of a new attack...
Vulnerability report
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software Denial of Service
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · 9.8.1
Decision summary
Direct answers before the deeper technical record.
What it is
CVE-2025-20362 is an unauthenticated vulnerability affecting Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall.... Update: On November 5, 2025, Cisco became aware of a new attack...
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV. Also confirmed by third-party sources.
Who is affected?
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.8.1.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases that are affected by CVE-2025-20333 and CVE-2025-20362. This attack can cause unpatched devices to unexpectedly reload, leading to denial of service (DoS) conditions. Cisco strongly recommends that all customers upgrade to the fixed software releases that are listed in the Fixed Software ["#fs"] section of this advisory.
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 access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication.
This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on a device. A successful exploit could allow the attacker to access a restricted URL without authentication.
Exploitation evidence
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
CVE
A trusted third party reported exploitation.
Nuclei Templates
Public scanner or PoC coverage increases practical exploitability.
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CVE First | 2026-06-01 10:41 UTC |
| CISA | 2026-06-02 14:06 UTC |
| The Shadowserver | 2026-06-27 10:15 UTC |
Detection
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-20362.yaml | 01 Jun 2026 |
Risk and context
CVSS v3.1
Potential damage if exploited. Separate from whether attackers are using it.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS
87.1%
Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
10:15 UTC
Exploitation attested by an external source
14:21 UTC
Public proof-of-concept code published
14:06 UTC
Listed in the CISA Known Exploited Vulnerabilities catalog
15:34 UTC
Scanner coverage available
10:41 UTC
High-confidence, third-party attested exploitation
16:12 UTC
Vulnerability disclosed publicly
19:15 UTC
Identifier reserved by the CNA
Pro API
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
GET /api/v2/pro/kevs/CVE-2025-20362
Free JSON includes basic KEV fields{
"cve_id": "CVE-2025-20362",
"confidence": "Confirmed",
"cvss_score": 6.5,
"cvss_estimated": false,
"epss_score": 0.87085,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}