CVE-2026-126254: Fortinet FortiOS · Denial of Service
Affects Fortinet FortiOSSource CVE Database V5
Public exploit available · CVSS 9.6 Critical · patch available : patch Fortinet FortiOS as a priority.
Data as of 11 Nov 2026, 21:49 UTC
Thin evidence
One scorer or none| CNA (fortinet) | CVSS 3.1 | 9.6 |
|---|
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H/E:F/RL:O/RC:CExploitation evidence
Disclosed: evidence found.
CVE published 11 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| FortinetFortiOS | Affected
| Fixed in– |
AI-suggested
Fortinet has released official patches addressing this vulnerability. Users should apply the provided fixes to affected FortiOS versions promptly to mitigate the risk. Since an official fix is available, remediation involves updating to patched versions as per Fortinet's guidance.
Description
CVE-2026-126254 is a critical numeric truncation error vulnerability in Fortinet FortiOS versions 7.2.0 through 7.2.13, 7.4.0 through 7.4.12, 7.6.0 through 7.6.7, and 8.0.0 through 8.0.1. It allows a configured iBGP neighbor to send malicious or malformed attributes that can cause denial of service to all connected routers.