Applied Cybernetics Group
Threat intel → detection pipeline
Friday, September 18, 2026
Data as of 13:09 UTC

Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability

Added to KEV
2026-09-09
Federal due date
2026-09-12
Vendor
Fortinet
Product
Multiple Products
EPSS
83.2th percentile (score 0.024, as of 2026-09-16)
NVD CVSS v3.1
8.1 (HIGH)
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2025-25249

CISA short description

Fortinet FortiOS, FortiSwitchManager, and FortiSASE contain a heap-based buffer overflow vulnerability that allows an attacker to execute unauthorized code or commands via specially crafted packets.

Required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

NVD description

A heap-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2.0 through 7.2.11, FortiOS 7.0.0 through 7.0.17, FortiOS 6.4 all versions, FortiSwitchManager 7.2.0 through 7.2.6, FortiSwitchManager 7.0.0 through 7.0.5 allows attacker to execute unauthorized code or commands via specially crafted packets

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.