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Adaptive Security Appliance SoftwareOperating system · Cisco

CVE-2026-20070

MEDIUM · 6.1 CVSS v3.1 Published 2026-03-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in the VPN web services component of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a browser that is accessing an affected device.  This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by persuading a user to follow a link to a malicious website that is designed to submit malicious input to the affected application. A successful exploit could allow the attacker to execute arbitrary HTML or script code in the browser in the context of the VPN web server.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a reflected cross-site scripting (XSS) vulnerability in the VPN web services component of Cisco Secure Firewall ASA and FTD appliances. The vulnerability stems from improper validation of user-supplied input in HTTP requests, allowing an unauthenticated attacker to inject malicious scripts via crafted URLs. Successful exploitation enables arbitrary HTML or script execution in the context of a user's browser when accessing the VPN web interface.

MitigationApply the Cisco security patch for CVE-2026-20070 when released. In the interim, restrict access to the VPN web management interface to trusted networks only and educate users about avoiding untrusted links.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Adaptive Security Appliance SoftwareOperating system
Affected:= 9.12.1= 9.12.1.2= 9.12.1.3= 9.12.2= 9.12.2.1= 9.12.2.4= 9.12.2.5= 9.12.2.9= 9.12.3= 9.12.3.2= 9.12.3.7= 9.12.3.9
Secure Firewall Threat DefenseApplication
Affected:= 6.4.0= 6.4.0.1= 6.4.0.2= 6.4.0.3= 6.4.0.4= 6.4.0.5= 6.4.0.6= 6.4.0.7= 6.4.0.8= 6.4.0.9= 6.4.0.10= 6.4.0.11

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the Cisco appliance type
    Determine if the device is running Cisco ASA (Adaptive Security Appliance) or FTD (Firepower Threat Defense) using the CLI command 'show version' or via the management interface.
    Affected if The device is either an ASA or FTD appliance.
  2. Check the installed ASA version
    Run 'show version' on the ASA CLI and note the software version number. Compare against the affected list: 9.12.1, 9.12.1.2, 9.12.1.3, 9.12.2, 9.12.2.1, 9.12.2.4, 9.12.2.5, 9.12.2.9, 9.12.3, 9.12.3.2, 9.12.3.7, 9.12.3.9.
    Affected if The ASA software version matches exactly one of these versions.
  3. Check the installed FTD version
    Run 'show version' on the FTD device and note the software version number. Compare against the affected list: 6.4.0 through 6.4.0.11 (inclusive).
    Affected if The FTD software version is 6.4.0.x where x is 0 through 11.
  4. Verify VPN web services are enabled
    Check if the ASA/FTD VPN web management interface (WebVPN or SSL VPN) is enabled via 'show run webvpn' or through the ASDM/FDM management interface under VPN configuration.
    Affected if WebVPN or SSL VPN web services are currently enabled on the appliance.
  5. Confirm VPN web interface accessibility
    Determine if the VPN web management port (typically 443) is reachable from untrusted networks by reviewing access lists, interface security levels, or performing a network scan from an external location.
    Affected if The VPN web interface is exposed to networks outside the trusted internal network.

A user is affected if they are running ASA version 9.12.x or FTD version 6.4.0.x with the VPN web services interface enabled and accessible, even from a single affected version match.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Cisco security patch for CVE-2026-20070 when released. In the interim, restrict access to the VPN web management interface to trusted networks only and educate users about avoiding untrusted links.

Fix this in Adaptive Security Appliance Software Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,900
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20070 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data