FortiOS 6.4.3-7.6.0 HTTP Request Smuggling (Unauthenticated)
CVE-2025-55018 Published on February 10, 2026
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
Vulnerability Analysis
CVE-2025-55018 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and no impact on availability.
Weakness Type
What is a HTTP Request Smuggling Vulnerability?
When malformed or abnormal HTTP requests are interpreted by one or more entities in the data flow between the user and the web server, such as a proxy or firewall, they can be interpreted inconsistently, allowing the attacker to "smuggle" a request to one device without the other device being aware of it.
CVE-2025-55018 has been classified to as a HTTP Request Smuggling vulnerability or weakness.
Products Associated with CVE-2025-55018
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Affected Versions
Fortinet FortiOS:- Version 7.6.0 is affected.
- Version 7.4.0, <= 7.4.9 is affected.
- Version 7.2.0, <= 7.2.13 is affected.
- Version 7.0.0, <= 7.0.19 is affected.
- Version 6.4.3, <= 6.4.16 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.