FortiAuthenticator: Use of Hard-coded Password
CVE-2026-126257 is a critical-severity use of hard-coded password vulnerability in FortiAuthenticator from Fortinet, with a CVSS 3.1 base score of 9.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected FortiAuthenticator versions: 8.0.0 through 8.0.3; 6.6.0 through 6.6.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.4% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of FortiAuthenticator you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on fortiguard.fortinet.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fortinet | FortiAuthenticator | 8.0.0 through 8.0.3; 6.6.0 through 6.6.10 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (fortinet.com).
Official description
A use of hard-coded password vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an unauthenticated attacker to bypass credential validation in certain circumstances outside of the attacker's control and gain unauthorized access.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Password
The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound authentication to external components.
How developers prevent this class of flaw
- For outbound authentication: store passwords outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible.
- For inbound authentication: Rather than hard-code a default username and password for first time logins, utilize a first login mode that requires the user to enter a unique strong password.
- Perform access control checks and limit which entities can access the feature that requires the hard-coded password. For example, a feature might only be enabled through the system console instead of through a network connection.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in FortiAuthenticator
- 8.3 High severity
- 9.1 Critical severity
- 8.2 High severity
- 7.2 High severity
- 7.5 High severity
- 7.2 High severity
Recent Use of Hard-coded Password vulnerabilities
- 10.0 Critical severity
- 10.0 Critical severity
- 7.4 High severity
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
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