FortiOS
CVE-2025-25255: Improperly Implemented Security Check for Standard in FortiOS, FortiProxy
An Improperly Implemented Security Check for Standard vulnerability [CWE-358] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.11, FortiProxy 7.2 all versions, FortiProxy 7.0.1 through 7.0.22 may allow an unauthenticated proxy user to bypass the domain fronting protection feature via crafted HTTP requests.
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 |
| FortiProxy 7.6.0 to 7.6.3 | 7.6.4 or later |
| FortiProxy 7.4.0 to 7.4.11 | 7.4.12 or later |
| FortiProxy 7.2.0 to 7.2.15 | Upgrade past 7.2.15; see the advisory |
| FortiProxy 7.0.1 to 7.0.22 | Upgrade past 7.0.22; see the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
An Improperly Implemented Security Check for Standard vulnerability [CWE-358] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.11, FortiProxy 7.2 all versions, FortiProxy 7.0.1 through 7.0.22 may allow an unauthenticated proxy user to bypass the domain fronting protection feature via crafted HTTP requests.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 10 Oct 2026.