# CVE-2026-126244: Fortinet FortiAuthenticator resource exhaustion denial of service

Source: https://junglewise.ai/threats/cve-2026-126244-a-allocation-of-resources-without-limits-or-throttling  
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-2026-126244 · Severity: high · CVSS 7.5 · Published 2026-11-11

FortiAuthenticator is an authentication and identity management platform used to secure access to corporate applications and networks. An unpatched system can be overwhelmed by an unauthenticated attacker with unlimited API requests, causing the service to become unavailable to legitimate users. This denial of service requires no credentials or user interaction and could interrupt access to critical authentication services.

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

## Quick answers

**Is CVE-2026-126244 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-126244 being exploited in the wild.

**How severe is CVE-2026-126244?** High severity, with a CVSS score of 7.5, 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-2026-126244?** 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-2026-126244 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-126244?** 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

The FastAPI-based API endpoint in FortiAuthenticator lacks rate limiting or resource quotas, allowing an unauthenticated attacker to exhaust server resources through repeated requests (CWE-770). The vulnerability affects versions 8.0.0–8.0.3 and 6.6.0–6.6.10, with fixes available in 8.0.4+ and 6.6.11+ respectively. An attacker on the network can trigger denial of service without authentication or prior system compromise.

## Affected products

- Fortinet FortiAuthenticator 8.0.0 through 8.0.3, 6.6.0 through 6.6.10

## Timeline

- 2026-11-10: disclosed
- 2026-11-11: advisory

## References

- [https://fortiguard.fortinet.com/psirt/FG-IR-26-258](https://fortiguard.fortinet.com/psirt/FG-IR-26-258)

## 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)