VulnerabilityPublished 4 Mar 2026

CVE-2026-20064: Cisco Secure Firewall Threat Defense (FTD) Software · NULL Pointer Dereference

Affects Cisco Secure Firewall Threat Defense (FTD) SoftwareSource CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

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 29 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 Threat Defense (FTD) Software	Affected 6.4.0 – 7.7.10.1 75 affected builds	Fixed in–

AI-suggested

Restrict CLI access strictly to trusted administrators and enforce strong authentication mechanisms, such as multi-factor authentication, to reduce the risk of unauthorized local access.
Monitor and audit CLI command usage to detect unusual or unauthorized command execution attempts that could indicate exploitation attempts.
Implement network segmentation and access controls to limit the number of users and systems that can reach the Cisco FTD management interfaces.
Stay informed on Cisco security advisories and apply patches or software updates promptly once Cisco releases fixes addressing this vulnerability.
Consider deploying redundant firewall devices or failover mechanisms to minimize service disruption in case of device reloads.
Conduct regular security training for administrators to recognize and prevent misuse of privileged access.
Use endpoint protection and network monitoring tools to detect potential insider threats or lateral movement that could lead to exploitation.
If patching is delayed, consider temporary configuration changes that limit command execution capabilities for low-privileged users.

Description

A vulnerability in of Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, local attacker to cause the device to unexpectedly reload, causing a denial of service (DoS) condition. This vulnerability is due to improper validation of user-supplied input. An attacker with a low-privileged account could exploit this vulnerability by using crafted commands at the CLI prompt. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Impact

The primary impact of CVE-2026-20064 is a denial of service condition caused by the unexpected reload of Cisco Secure Firewall Threat Defense devices. For organizations worldwide, this can lead to temporary loss of firewall protection, exposing internal networks to external threats during the downtime. Critical environments relying on continuous firewall availability, such as financial institutions, healthcare providers, government agencies, and large enterprises, may experience operational disruptions, compliance violations, and increased risk of secondary attacks during the outage. The requirement for local authenticated access limits remote exploitation risk but does not eliminate insider threat or lateral movement scenarios. The broad range of affected software versions means many organizations could be vulnerable if running unpatched Cisco FTD instances. Although no confidentiality or integrity compromise is indicated, the availability impact alone can have cascading effects on network security posture and business continuity.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-cmd-inj-mTzGZexf (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Mar 2026, 20:22 UTC

Technical details

References

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