CVE-2025-25249 Fortinet Multiple Products Heap-based Buffer Overflow

What is CVE-2025-25249?

CVE-2025-25249 is a high-severity memory corruption vulnerability in Fortinet Fortios, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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

Weakness: CWE-787, CWE-122

Which versions are affected by CVE-2025-25249?

It affects 4 products.

Products include Fortinet Fortios, Fortinet Fortisase, Fortinet Fortiswitchmanager, Siemens Ruggedcom Ape1808 Firmware.

How do I fix CVE-2025-25249?

No fix has been published for CVE-2025-25249 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 12 Sep 2026.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-25249 being exploited?

Yes. Attackers have exploited CVE-2025-25249 in the wild since at least 9 Sep 2026.

Other vulnerabilities in Fortinet Fortios

• CVE-2024-23113 Fortinet Multiple Products Format String Exploited Critical 9.8
• CVE-2022-40684 Fortinet Multiple Products Authentication Bypass Exploited Critical 9.8
• CVE-2024-55591 Fortinet FortiOS and FortiProxy Authentication Bypass Exploited Critical 9.6
• CVE-2024-21762 Fortinet FortiOS Out-of-Bound Write Exploited Critical 9.6
• CVE-2022-42475 Fortinet FortiOS Heap-Based Buffer Overflow Exploited Critical 9.3

All Fortinet Fortios vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-mj8x-m8f5-x4w8.