FortiOS
CVE-2025-53843: Stack-based buffer overflow in FortiOS
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
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| FortiOS 7.6.0 to 7.6.3 | 7.6.4 or later |
| FortiOS 7.4.0 to 7.4.8 | 7.4.9 or later |
| FortiOS 7.2.0 to 7.2.12 | Upgrade past 7.2.12; see the advisory |
| FortiOS 7.0.0 to 7.0.18 | Upgrade past 7.0.18; see the advisory |
| FortiOS 6.4.0 to 6.4.16 | Upgrade past 6.4.16; see the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 10 Oct 2026.