Fortinet FortiOS up to 7.6.0 HTTP Request request smuggling

Summaryinfo

A vulnerability categorized as problematic has been discovered in Fortinet FortiOS up to 6.4.16/7.0.19/7.2.13/7.4.9/7.6.0. This issue affects some unknown processing of the component HTTP Request Handler. Such manipulation leads to request smuggling. This vulnerability is documented as CVE-2025-55018. The attack can be executed remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Fortinet FortiOS up to 6.4.16/7.0.19/7.2.13/7.4.9/7.6.0. Affected by this issue is an unknown functionality of the component HTTP Request Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. Using CWE to declare the problem leads to CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. Impacted is integrity. CVE summarizes:

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

The advisory is available at fortiguard.fortinet.com. This vulnerability is handled as CVE-2025-55018 since 08/05/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

Upgrading to version 7.4.10 or 7.6.1 eliminates this vulnerability.

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Productinfo

Type

• Firewall Software

Vendor

• Fortinet

Name

• FortiOS

Version

• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5
• 6.4.6
• 6.4.7
• 6.4.8
• 6.4.9
• 6.4.10
• 6.4.11
• 6.4.12
• 6.4.13
• 6.4.14
• 6.4.15
• 6.4.16
• 7.0
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.7
• 7.0.8
• 7.0.9
• 7.0.10
• 7.0.11
• 7.0.12
• 7.0.13
• 7.0.14
• 7.0.15
• 7.0.16
• 7.0.17
• 7.0.18
• 7.0.19
• 7.1
• 7.2
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.2.10
• 7.2.11
• 7.2.12
• 7.2.13
• 7.3
• 7.4
• 7.4.0
• 7.4.1
• 7.4.2
• 7.4.3
• 7.4.4
• 7.4.5
• 7.4.6
• 7.4.7
• 7.4.8
• 7.4.9
• 7.5
• 7.6.0

License

• commercial

Website

• Vendor: https://www.fortinet.com/

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