CVE-2025-25249

A heap-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0...

7.4 HighIn KEV

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

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

3.74%Up 3.7 points since Jan 14, 2026

What each source reports

CVE List Score used 7.4

Record: CVE-2025-25249
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:W/RC:C
Weakness: CWE-122
Updated: 2026-11-02

EUVDEUVD-2026-2223 7.4

Record: EUVD-2026-2223
CVSS 3.1: 7.4 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:W/RC:C
Updated: 2026-11-02

GitHub AdvisoriesGHSA-mj8x-m8f5-x4w8 8.1

A heap-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0...

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 6.4.0 through 6.4.16, FortiSASE 25.2.b, FortiSASE 25.1.a.2, 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

Record: GHSA-mj8x-m8f5-x4w8
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-122, CWE-787
Updated: 2026-11-02

CISA KEV No score

Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability

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.

Record: CVE-2025-25249
Weakness: CWE-122, CWE-787
Updated: 2026-11-02

NVD 8.1

Record: CVE-2025-25249
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-122, CWE-787
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 3, 2026	exploitation
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, CISA KEV, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-25249 is a high vulnerability (CVSS 7.4) in Fortinet Fortios, published January 13, 2026. CISA lists it as known to be exploited, since September 9, 2026. EUVD reports exploitation since September 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.74%, the 89th percentile. No source names a fixed version.