CVE-2025-31366

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-14 · updated 2026-10-18
Weakness: CWE-79

Description

An Improper Neutralization of Input During Web Page Generation vulnerability [CWE-79] 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, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4 all versions, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions, FortiSASE 25.2.a may allow an unauthenticated attacker to perform a reflected cross site scripting (XSS) via crafted HTTP requests.

Affected products

Fortinet FortiOS (FortiGate): from 6.4.0 before 7.4.9; from 7.6.0 before 7.6.4 — fixed in 7.4.9, 7.6.4
Fortinet FortiProxy: from 7.0.0 before 7.6.4 — fixed in 7.6.4
Fortinet FortiSASE: 25.3.40

How to fix

Upgrade to a fixed version: Fortinet FortiOS (FortiGate) 7.4.9, 7.6.4; Fortinet FortiProxy 7.6.4. Check the vendor advisory for mitigations.

References

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