CVE-2025-55018: Request smuggling attack in FortiOS
An HTTP request smuggling vulnerability [CWE-444] in FortiOS may allow an unauthenticated attacker to smuggle an unlogged http request through the firewall policies via a specially crafted header
Other sources
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
— MITRE
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2025-55018?
CVE-2025-55018 is considered a high severity vulnerability due to its potential for HTTP request smuggling attacks.
How do I fix CVE-2025-55018?
To mitigate CVE-2025-55018, it is recommended to upgrade FortiOS to the latest version as specified in the vendor's advisory.
Which versions of FortiOS are affected by CVE-2025-55018?
CVE-2025-55018 affects FortiOS versions 7.0, 7.2, 7.4.0 to 7.4.9, and 7.6.1 and earlier.
Can CVE-2025-55018 be exploited remotely?
Yes, CVE-2025-55018 can be exploited remotely by an unauthenticated attacker.
What type of attack does CVE-2025-55018 facilitate?
CVE-2025-55018 facilitates HTTP request smuggling attacks that allow attackers to bypass firewall policies.