CVE-2025-25249
Published 2026-01-13 · Updated 2026-10-07 · Source psirt@fortinet.com
Summary
CVE-2025-25249 is a high-severity (CVSS 8.1) vulnerability in Fortinet Multiple Products. CISA added it to the Known Exploited Vulnerabilities catalog on September 9, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by September 12, 2026. CISA does not currently list it as used in ransomware campaigns. Fortinet has 32 vulnerabilities in the KEV catalog, 14 of them linked to ransomware.
All 32 known-exploited Fortinet vulnerabilities →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
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Fortinet — Multiple Products
Name: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
Date added: 2026-09-09 · Due: 2026-09-12
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.