Quick answers
- Is CVE-2026-126254 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-126254 being exploited in the wild.
- How severe is CVE-2026-126254?
- Critical severity, with a CVSS score of 9.6, published 11 November 2026.
- Which products and versions are affected?
- Fortinet FortiOS 8.0.0 through 8.0.1, 7.6.0 through 7.6.7, 7.4.0 through 7.4.12, 7.2.0 through 7.2.13; Fortinet Fortisase 25.1 through 26.3.1, 26.2 all versions.
- Is there a fix for CVE-2026-126254?
- Yes: fixed in FortiOS 8.0.2 or above, 7.6.8 or above, 7.4.13 or above, 7.2.14 or above; FortiSASE 26.3.2 or above (26.3.1 and earlier affected; 26.2 and earlier require migration to fixed release). Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-126254 attacked?
- It is attacked over the network, in an operating system.
- Am I affected by CVE-2026-126254?
- Check whether you run Fortinet FortiOS or Fortinet Fortisase 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: FortiOS 8.0.2 or above, 7.6.8 or above, 7.4.13 or above, 7.2.14 or above; FortiSASE 26.3.2 or above (26.3.1 and earlier affected; 26.2 and earlier require migration to fixed release)
Technical details
A numeric truncation error (CWE-197) in the FortiOS and FortiSASE BGP daemon allows a configured iBGP neighbor to send specially crafted malformed attributes that propagate to all connected routers. The vulnerability requires authentication as a configured BGP neighbor and operates over the network. Exploitation causes denial of service impact.
Affected products
- Fortinet FortiOS 8.0.0 through 8.0.1, 7.6.0 through 7.6.7, 7.4.0 through 7.4.12, 7.2.0 through 7.2.13
- Fortinet FortiSASE 25.1 through 26.3.1, 26.2 all versions
Timeline
- 2026-11-10: disclosed