Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
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
What happened
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
CISA lists it as exploited, added 09 Sep 2026.
Does it affect you
Names Fortinet FortiGate (FortiOS). Enter the product and version you run to place it against the affected range the vendor published.
What to do
- Follow the vendor advisory for the fixed release and any interim mitigation.
fortiguard.fortinet.com - 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.
cisa.gov
CISA’s notes for this entry:
- fortiguard.fortinet.com/psirt/FG-IR-25-084
- BOD 26-04: cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Forensics Triage Requirements: cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov/vuln/detail/CVE-2025-25249
Affected, as published to NVD
- forti-os
- Fortinet FortiGate (FortiOS): 6.4.0 up to the fix in 7.0.18
The record
- NVD status
- Analyzed
- Published
- 13 Jan 2026, last modified 07 Oct 2026 (NVD)
- Severity
- CVSS 3.1 base score 9.8, Critical — computed here from the vector; NVD states 9.8.
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness
- CWE-122 Heap-based Buffer Overflow, CWE-787 Out-of-bounds Write (NVD; names by MITRE)
- Exploitation
- Listed in CISA’s Known Exploited Vulnerabilities catalogue since 09 Sep 2026; federal remediation due 12 Sep 2026. CISA entry
- Exploit probability
- EPSS 3.8%, 90th percentile — FIRST, scored 23 Oct 2026. FIRST EPSS
- Vendor
- Fortinet · Multiple Products (CISA)
References on the NVD record
- fortiguard.fortinet.com/psirt/FG-IR-25-084MitigationVendor Advisory
- cert-portal.siemens.com/productcert/html/ssa-864900.htmlThird Party Advisory
- socradar.io/blog/cve-2025-25249-pivotc2-fortigate-rat/ExploitThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-25249US Government Resource
Reporting that names this identifier
- Fortinet Code Execution Flaw Exploited in PivotC2 RAT Attacks — SecurityWeek, 1 mo ago
- CISA Adds Four Known Exploited Vulnerabilities to Catalog — CISA, 2 mo ago
Sources
The verdict above is computed from the products and versions you entered and the affected ranges the vendor published to NVD. It does not inspect your environment, and this site never reports a product as unaffected: why.