CVE-2025-25249
Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
Fortinet Multiple Products
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
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 9 September 2026. US federal agencies were required to remediate it by 12 September 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 2.4%, which is higher than 83.2% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2025-25249 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2025-25249.
What does CVE-2025-25249 affect?
CVE-2025-25249 affects Fortinet Multiple Products. 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
How severe is CVE-2025-25249?
CVE-2025-25249 is rated HIGH with a CVSS base score of 8.1. EPSS puts the probability of exploitation in the next 30 days at 2.4%, higher than 83.2% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 12 September 2026.
How should organisations respond to CVE-2025-25249?
Apply the vendor patch for Fortinet Multiple Products as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.