VulnerabilityPublished 4 Mar 2026

CVE-2026-20007: Cisco Secure Firewall Threat Defense (FTD) Software · Improper Access Control

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

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Not known to be exploited · CVSS 5.8 Medium.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.8Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: None
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: 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: 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 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 – 7.7.0 73 affected builds	Fixed in–

AI-suggested

Organizations should immediately identify and inventory all Cisco Secure Firewall Threat Defense (FTD) devices running affected versions (6.4.0 through 7.7.0). Cisco is expected to release patches or updates addressing this logic error; applying these updates promptly is critical. In the interim, administrators should review and tighten Snort rule configurations, focusing on rules that inspect tunneled or encapsulated traffic, to minimize the risk of bypass. Employing additional layers of network security, such as endpoint detection and response (EDR) and network segmentation, can reduce exposure. Monitoring firewall logs for anomalous traffic patterns that could indicate attempts to exploit this vulnerability is advised. Network traffic should be analyzed for inconsistencies between inner and outer packet inspections. Where possible, disabling or limiting the use of complex tunneling protocols that may trigger this issue can reduce attack vectors. Finally, organizations should engage in threat hunting exercises to detect any signs of exploitation and update incident response plans accordingly.

Description

A vulnerability in the Snort 2 and Snort 3 deep packet inspection of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Snort rules and allow traffic onto the network that should have been dropped. This vulnerability is due to a logic error in the integration of the Snort Engine rules with Cisco Secure FTD Software that could allow different Snort rules to be hit when deep inspection of the packet is performed for the inner and outer connections. An attacker could exploit this vulnerability by sending crafted traffic to a targeted device that would hit configured Snort rules. A successful exploit could allow the attacker to send traffic to a network where it should have been denied.

Impact

The primary impact of CVE-2026-20007 is the potential bypass of firewall security policies enforced by Snort rules within Cisco Secure FTD devices. This can allow unauthorized or malicious traffic to enter networks that would otherwise be blocked, undermining the integrity of network defenses. Organizations relying on Cisco Secure FTD for perimeter or internal segmentation security could face increased risk of intrusion, lateral movement, or data exfiltration attempts that evade detection. Although confidentiality and availability are not directly affected, the ability to bypass security controls can facilitate further attacks that compromise these aspects. The widespread use of Cisco Secure FTD in enterprise, government, and critical infrastructure sectors globally means that many organizations could be exposed. The lack of required authentication or user interaction lowers the barrier for attackers, increasing the threat surface. If exploited in targeted attacks, this vulnerability could enable advanced persistent threats (APTs) or cybercriminals to maintain stealthy access within networks.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort-bypass-rLggKzVF (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Mar 2026, 20:15 UTC

Technical details

References

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