Quick answers
- Is CVE-2026-126239 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-126239 being exploited in the wild.
- How severe is CVE-2026-126239?
- High severity, with a CVSS score of 7.5, published 11 November 2026.
- Which products and versions are affected?
- Fortinet FortiAuthenticator 6.6.0 through 6.6.10, 8.0.0 through 8.0.3.
- Is there a fix for CVE-2026-126239?
- Yes: fixed in FortiAuthenticator 6.6.11 or above, 8.0.4 or above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-126239 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-126239?
- 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 6.6.11 or above, 8.0.4 or above
Technical details
A stack-based buffer overflow (CWE-121) in the API component allows unauthenticated remote attackers to crash the FSSO subsystem via malformed HTTP requests. The vulnerability requires no authentication and can be exploited over the network. The impact is denial of service; code execution potential is noted in the advisory's impact statement but the primary demonstrated risk is subsystem crash.
Affected products
- Fortinet FortiAuthenticator 6.6.0 through 6.6.10, 8.0.0 through 8.0.3
Timeline
- 2026-11-10: disclosed: Initial publication