# CVE-2026-126240: Fortinet FortiAuthenticator LDAP injection authentication bypass

Source: https://junglewise.ai/threats/cve-2026-126240-a-improper-neutralization-of-special-elements-used-in-an-ldap  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-11. Updated: 2026-11-11  
License: CC BY 4.0 with a link back

CVE-2026-126240 · Severity: high · CVSS 8.2 · Published 2026-11-11

FortiAuthenticator is an authentication server used to manage user access and identity verification. An LDAP injection vulnerability allows an authenticated attacker to bypass authentication if the upstream identity provider is compromised or misconfigured, potentially gaining unauthorized access to protected systems.

Technologies: [Fortinet FortiAuthenticator](https://junglewise.ai/threats/technologies/fortiauthenticator). Vendors: [Fortinet](https://junglewise.ai/threats/vendors/fortinet).

## Quick answers

**Is CVE-2026-126240 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126240 being exploited in the wild.

**How severe is CVE-2026-126240?** High severity, with a CVSS score of 8.2, published 11 November 2026.

**Which products and versions are affected?** Fortinet FortiAuthenticator 8.0.0 through 8.0.3, 6.6.0 through 6.6.10.

**Is there a fix for CVE-2026-126240?** Yes: fixed in FortiAuthenticator 8.0.4 or above, 6.6.11 or above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-126240 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-126240?** Check whether you run Fortinet FortiAuthenticator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in FortiAuthenticator 8.0.4 or above, 6.6.11 or above

## Technical details

An improper neutralization of special elements in LDAP queries (LDAP injection) in the FortiAuthenticator API allows authenticated attackers to bypass authentication. The vulnerability requires either a malicious/compromised upstream identity provider (IdP) or an IdP configuration that permits user control of the NameID or SAML attribute used as the username.

## Affected products

- Fortinet FortiAuthenticator 8.0.0 through 8.0.3, 6.6.0 through 6.6.10

## Timeline

- 2026-11-10: disclosed

## References

- [https://fortiguard.fortinet.com/psirt/FG-IR-26-255](https://fortiguard.fortinet.com/psirt/FG-IR-26-255)

## Related threats

- [Fortinet FortiAuthenticator hard-coded password authentication bypass](https://junglewise.ai/threats/cve-2026-126257-a-use-of-hard-coded-password-vulnerability-in-fortinet)
- [Fortinet FortiAuthenticator SQL injection](https://junglewise.ai/threats/cve-2026-126252-a-improper-neutralization-of-special-elements-used-in-an-sql)
- [Fortinet FortiAuthenticator incorrect authorization](https://junglewise.ai/threats/cve-2026-126251-a-incorrect-authorization-vulnerability-in-fortinet)
- [Fortinet FortiAuthenticator authorization bypass DoS](https://junglewise.ai/threats/cve-2026-126250-a-incorrect-authorization-vulnerability-in-fortinet)
- [Fortinet FortiAuthenticator privilege escalation in GUI](https://junglewise.ai/threats/cve-2026-126249-a-improper-privilege-management-vulnerability-in-fortinet)