FortiOS
CVE-2025-55018: HTTP request smuggling in FortiOS
An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header
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 | 7.6.1 or later |
| FortiOS 7.4.0 to 7.4.9 | 7.4.10 or later |
| FortiOS 7.2.0 to 7.2.13 | Upgrade past 7.2.13; see the advisory |
| FortiOS 7.0.0 to 7.0.19 | Upgrade past 7.0.19; see the advisory |
| FortiOS 6.4.3 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
An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 10 Oct 2026.