Is CVE-2026-20349 actively exploited?

Yes. KEV Intelligence tracks CVE-2026-20349 as a known exploited vulnerability. Confidence is confirmed.

What exploitation activity has KEV Intelligence observed?

KEV Intelligence has not yet recorded sensor-observed exploitation attempts for CVE-2026-20349. Our sensors continue to monitor for activity targeting this CVE.

Which versions are affected?

CVE-2026-20349 affects Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure.... KEV Intelligence lists 197 version rows; examples include 9.16.1, 9.16.1.28, and 9.16.2.

Yes. CVE-2026-20349 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

CVE-2026-20349 Exploited in the Wild — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-20349 is an unauthenticated vulnerability affecting Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure.... A vulnerability in the Remote Access SSL VPN service for Cisco...

Is it exploited?

Yes. KEV Intelligence tracks this CVE as a known exploited vulnerability. Confidence is confirmed.

Who is affected?

Cisco / 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 for 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 insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device.

A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Vendor Product Affected Status

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.6.1 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.2.3 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.0.8 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.6.2 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.7.10 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.7.11 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.0.8.1 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.6.2.1 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.7.10.1 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.2.4 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.2.10.2 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.3 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.6.4 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 10.0.0 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.4 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.0.9 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.2.11 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.7 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.4.8 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.2.12 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 7.7.13 Affected

Cisco Cisco Secure Firewall Threat Defense (FTD) Software 10.0.2 Affected

Published: 11 Aug 2026
Exploitation Reported: 11 Aug 2026
Attack vector: Remote
Complexity: Low
Privileges: None
User interaction: None

CVE References

cisco-sa-asaftd-vpn-dos-dzv4mQFF sec.cloudapps.cisco.com · CVE Record https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurity...

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 11 Aug 2026

Independent exploitation attestation added to the KEV Intelligence record.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

Learn about Pro API access

Source	Added
CISA First	2026-08-11 18:59 UTC
CVE	2026-08-11 20:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets: 0
User-Agents: 0

Raw values available in Pro and Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No KEV Intelligence 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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS

—

Weaknesses

Improper Clearing of Heap Memory Before Release ('Heap Inspection') CWE-244

Recent mention · Cisco Security Advisory

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

A vulnerability in the Remote Access SSL VPN service for 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 advisory

Timeline

From disclosure to observed exploitation

11 Aug 2026
KEV confirmed by CVE

Exploitation attested by an external source
11 Aug 2026
Added to CISA KEV

Listed in the CISA Known Exploited Vulnerabilities catalog
11 Aug 2026
CVE published

Vulnerability disclosed publicly
08 Oct 2025
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.

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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-2026-20349

Free JSON includes basic KEV fields

{
  "cve_id": "CVE-2026-20349",
  "confidence": "Confirmed",
  "cvss_score": 8.6,
  "epss_score": null,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}

CVE-2026-20349