CVE-2025-25249: high-severity vulnerability in Fortinet FortiOS
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
Prioritize patching. It under exploitation confirmed by CISA and has an official Brazilian government alert.
Brazil's federal government published an alert, recommendation or bulletin that cites this vulnerability.
- CTIR Gov · ALERTA 86/2026 · 25 Sep 2026Vulnerabilidade crítica que afeta Múltiplos Produtos Fortinetread on gov.br ↗
- CISC Gov.br · 16 Sep 2026Boletim do CISC de Vulnerabilidadesread on gov.br ↗
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.
A heap memory overflow flaw in Fortinet FortiOS and FortiSwitchManager allows attackers to send specially crafted packets that overwrite memory and execute malicious code on the affected device. This is dangerous because it gives attackers complete control over the system.
Heap-based buffer overflow in FortiOS (6.4–7.6.3) and FortiSwitchManager (7.0.0–7.2.6) triggered by malformed packets without authentication requirements. Successful exploitation results in arbitrary code execution with device privileges, enabling full system compromise.
In the same product, most dangerous first.