CVE-2025-53843 Memory corruption in FortiOS

What is CVE-2025-53843?

CVE-2025-53843 is a medium-severity memory corruption vulnerability in Fortinet Fortios, published on 18 Nov 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A stack-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 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to execute unauthorized code or commands via specially crafted packets

Weakness: CWE-121

Which versions are affected by CVE-2025-53843?

It affects 1 product.

Products include Fortinet Fortios.

How do I fix CVE-2025-53843?

No fix has been published for CVE-2025-53843 yet. Limit exposure of the affected software until one is available.

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

Is CVE-2025-53843 being exploited?

There is no known exploitation of CVE-2025-53843 in the wild and no public exploit code.

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-69h7-jm2r-gmcg.