Netgate pfSense up to 2.9.0 Login Protection sshguard.conf os command injection

Summaryinfo

A vulnerability was found in Netgate pfSense up to 2.9.0. It has been rated as very critical. This issue affects some unknown processing of the file sshguard.conf of the component Login Protection. The manipulation leads to os command injection. This vulnerability is referenced as CVE-2026-111226. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Netgate pfSense up to 2.9.0. It has been rated as very critical. This issue affects an unknown function of the file sshguard.conf of the component Login Protection. The manipulation with an unknown input leads to a os command injection vulnerability. Using CWE to declare the problem leads to CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

pfSense CE 2.4.5 through 2.9.0 contains an OS command injection vulnerability that allows authenticated WebGUI users with Advanced Admin Access privilege to execute commands as root via Login Protection settings. Attackers can submit sshguard threshold, block time, or detection time values containing newlines or $(...) that are written unvalidated to sshguard.conf and sourced as root on restart.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-111226 since 10/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation requires an enhanced level of successful authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/15/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Firewall Software

Vendor

• Netgate

Name

• pfSense

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9.0

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Entryinfo

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