Skip to main content
ExploitedIn CISA KEV

CVE-2026-20349

Exploitation confirmed. First attested on 2026-08-11 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2026-08-11
  • WeaknessCWE-244

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2026-08-11Added to the CISA KEV catalogCISA KEV
  2. 2026-08-11Listed as exploited by GCVEGCVE
  3. 2026-08-11Exploitation first reportedCISA KEV
  4. 2026-08-1117:17CVE publishedNVD
  5. 2026-08-1119:40SSVC exploitation set to activeCISA-ADP

Versions per branch

NVD
Cisco ASA
BranchAffectedFixed in
9.16= 9.16.1no fix published
9.16= 9.16.1.28no fix published
9.16= 9.16.2no fix published
9.16= 9.16.2.3no fix published
9.16= 9.16.2.7no fix published
9.16= 9.16.2.11no fix published
9.16= 9.16.2.13no fix published
9.16= 9.16.2.14no fix published
9.16= 9.16.3no fix published
9.16= 9.16.3.3no fix published
9.16= 9.16.3.14no fix published
9.16= 9.16.3.15no fix published
Cisco secure firewall threat defense
BranchAffectedFixed in
7.0= 7.0.0no fix published
7.0= 7.0.0.1no fix published
7.0= 7.0.1no fix published
7.0= 7.0.1.1no fix published
7.0= 7.0.2no fix published
7.0= 7.0.2.1no fix published
7.0= 7.0.3no fix published
7.0= 7.0.4no fix published
7.0= 7.0.5no fix published
7.0= 7.0.6no fix published
7.0= 7.0.6.1no fix published
7.0= 7.0.6.2no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA2 products

As cisco, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareother versions: unknown
    Affected
    • = 9.16.1no fix stated
    • = 9.16.1.28no fix stated
    • = 9.16.2no fix stated
    • = 9.16.2.3no fix stated
    • = 9.16.2.7no fix stated
    • = 9.16.2.11no fix stated
    • = 9.16.2.13no fix stated
    • = 9.16.2.14no fix stated

    124 more version lines in the CVE record.

  • Cisco Secure Firewall Threat Defense (FTD) Softwareother versions: unknown
    Affected
    • = 7.0.0no fix stated
    • = 7.0.0.1no fix stated
    • = 7.0.1no fix stated
    • = 7.0.1.1no fix stated
    • = 7.0.2no fix stated
    • = 7.2.0no fix stated
    • = 7.0.2.1no fix stated
    • = 7.0.3no fix stated

    53 more version lines in the CVE record.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-09-16

Fix

  1. CISA’s 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.due 2026-08-14

Advisories and patches

Detection

read 2026-11-01 01:02 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2026-08-11
Patch Due Date
2026-08-14
Ransomware Use
Unknown
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.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
2026-08-11
Last Modified
2026-10-26
NVD status
Analyzed
GitHub Advisory
GHSA-8x4j-5v9x-9frv

Frequently asked questions

What is CVE-2026-20349?

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.

Is CVE-2026-20349 actively exploited?

Yes. CVE-2026-20349 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-08-14.

What is the CVSS score for CVE-2026-20349?

CVE-2026-20349 has a CVSS v3 base score of 8.6 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, August 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record