CVE-2025-55018
HTTP Request Smuggling in Fortinet FortiOS Allows Unauthorized Access
Publication date: 2026-02-10
Last updated on: 2026-02-23
Assigner: Fortinet, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| fortinet | fortios | 7.6.0 |
| fortinet | fortios | From 7.0.0 (inc) to 7.4.10 (exc) |
| fortinet | fortios | From 6.4.3 (inc) to 6.4.16 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an inconsistent interpretation of HTTP requests, known as 'HTTP request smuggling', in various versions of Fortinet FortiOS. It allows an unauthenticated attacker to send a specially crafted HTTP request header that can bypass normal firewall policies and smuggle an unlogged HTTP request through the firewall.
How can this vulnerability impact me? :
The vulnerability may allow an attacker to bypass firewall policies without authentication, potentially enabling them to send hidden or unlogged HTTP requests through the firewall. This can lead to unauthorized access or manipulation of network traffic, undermining the security controls in place.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know