VulnerabilityPublished 5 Feb 2026Updated 9 Feb 2026

CVE-2026-25815: Fortinet FortiOS · Use of Default Cryptographic Key

Affects Fortinet FortiOSSource CVE Database V5

Not known to be exploited · CVSS 3.2 Low.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

3.2Low

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: 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: None: There is no loss of integrity within 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 5 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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
FortinetFortiOS	Affected <=7.6.6	Fixed in–

AI-suggested

European organizations should immediately audit their FortiOS devices to determine if the default cryptographic key setting is in use for LDAP credential encryption. They should enable the non-default encryption option that uses unique cryptographic keys per installation, despite potential disruptions, and plan for operational adjustments accordingly. To minimize disruption, testing this configuration in controlled environments before widespread deployment is advised. Additionally, organizations should restrict local access to FortiOS device configuration files through strict access controls, monitoring, and logging to detect unauthorized access attempts. Employing network segmentation and limiting administrative privileges can reduce the risk of attackers obtaining local access. Regularly updating FortiOS to the latest versions, once patches or improved configurations are available, is critical. Organizations should also consider implementing multi-factor authentication for LDAP services and monitoring for anomalous authentication activities that might indicate credential misuse. Finally, educating administrators about the risks of default cryptographic keys and the importance of secure configuration management will help prevent similar issues.

Description

Fortinet FortiOS through 7.6.6 allows attackers to decrypt LDAP credentials stored in device configuration files, as exploited in the wild from 2025-12-16 through 2026 (by default, the encryption key is the same across all customers' installations). NOTE: the Supplier's position is that the instance of CWE-1394 is not a vulnerability because customers "are supposed to enable" a non-default option that eliminates the weakness. However, that non-default option can disrupt functionality as shown in the "Managing FortiGates with private data encryption" document, and is therefore intentionally not a default option.

Impact

For European organizations, the exposure of LDAP credentials due to this vulnerability can lead to unauthorized access to directory services, which are critical for authentication and authorization in enterprise environments. This could facilitate lateral movement, privilege escalation, and data exfiltration if attackers gain footholds within networks. Although the vulnerability requires local access to device configuration files, insider threats or attackers who have already compromised network segments could exploit it. The impact is particularly significant for sectors relying heavily on Fortinet FortiOS devices for network security and LDAP-based authentication, such as government agencies, financial institutions, healthcare providers, and critical infrastructure operators. The confidentiality breach of LDAP credentials could undermine trust in identity management systems and complicate incident response efforts. However, the lack of impact on integrity and availability, combined with the high attack complexity and local access requirement, limits the overall risk. Still, organizations that do not enable the recommended encryption option remain vulnerable to credential compromise, which could cascade into broader security incidents.

CWE-1394Use of Default Cryptographic Key (opens in a new tab)
Base weakness
The product uses a default cryptographic key for potentially critical functionality.
Requirements
Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
Architecture and Design
Force the administrator to change the credential upon installation.
Installation · Operation
The product administrator could change the defaults upon installation or during operation.
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Feb 2026, 07:14 UTC

WeaknessesCWE-1394

Technical details

References

Community reviews

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