VulnerabilityPublished 4 Mar 2026

CVE-2026-20102: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · Cross-site Scripting

Affects Cisco Secure Firewall Adaptive Security Appliance (ASA) SoftwareSource CVE Database V5

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Not known to be exploited · CVSS 6.1 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software	Affected 9.16.1 – 9.23.1.19 28 affected builds	Fixed in–
CiscoCisco Secure Firewall Threat Defense (FTD) Software	Affected 7.0.0 – 7.1.0.3 8 affected builds	Fixed in–

AI-suggested

To mitigate CVE-2026-20102, organizations should: 1) Apply Cisco’s security patches or updates as soon as they become available for all affected ASA and FTD software versions. 2) Implement strict input validation and output encoding on the SAML SSO web interface to neutralize malicious input and prevent script injection. 3) Employ web application firewalls (WAFs) or intrusion prevention systems (IPS) with rules to detect and block reflected XSS attack patterns targeting the firewall management interface. 4) Educate users and administrators about phishing risks and the dangers of clicking unsolicited or suspicious links, especially those purporting to be related to firewall or VPN access. 5) Restrict access to the firewall management interface to trusted networks and VPNs, minimizing exposure to untrusted users. 6) Monitor firewall logs and network traffic for unusual activity indicative of attempted exploitation or reconnaissance. 7) Consider implementing multi-factor authentication (MFA) for firewall management access to reduce the impact of stolen session tokens. 8) Regularly review and update security policies related to SAML SSO configurations and web interface exposure. These measures combined will reduce the risk of exploitation and limit potential damage.

Description

A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall 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 the SAML feature and access sensitive, browser-based information. This vulnerability is due to insufficient input validation of multiple HTTP parameters. An attacker could exploit this vulnerability by persuading a user to access a malicious link. A successful exploit could allow the attacker to conduct a reflected XSS attack through an affected device.

Impact

The impact of CVE-2026-20102 is primarily on confidentiality and integrity of information accessed via the affected firewall’s web interface. Successful exploitation allows attackers to execute arbitrary scripts in the context of the victim’s browser session, potentially stealing session cookies, authentication tokens, or other sensitive data. This can lead to unauthorized access to firewall management functions or network resources protected by the firewall. While availability is not directly affected, the compromise of firewall management could enable further attacks that disrupt network operations. Organizations relying on Cisco Secure Firewall ASA and FTD for perimeter security, VPN access, and SAML-based single sign-on are at risk of targeted phishing campaigns leveraging this vulnerability. The broad range of affected versions indicates a large attack surface globally. The requirement for user interaction reduces the likelihood of automated widespread exploitation but does not eliminate risk, especially in environments with high-value targets or sophisticated threat actors. The absence of known exploits in the wild currently limits immediate impact but does not preclude future exploitation. Overall, the vulnerability could facilitate lateral movement, privilege escalation, and data exfiltration in compromised networks.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-saml-LktTrwZP (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Mar 2026, 18:32 UTC

Technical details

References

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