CVE-2026-4742
HTTP Request Smuggling in LiteIDE http_parser.C Before x
Publication date: 2026-03-24
Last updated on: 2026-05-05
Assigner: Government Technology Agency of Singapore Cyber Security Group (GovTech CSG)
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| visualfc | liteide | to 38.4 (exc) |
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
How can this vulnerability impact me? :
This vulnerability can impact you by allowing attackers to exploit the inconsistent parsing of HTTP Transfer-Encoding headers to perform HTTP Request/Response Smuggling attacks. Such attacks can lead to bypassing security controls, injecting malicious HTTP requests, or manipulating HTTP traffic in unintended ways.
As a result, attackers might be able to conduct unauthorized actions, compromise data integrity, or disrupt normal communication between clients and servers using the affected liteide software.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
Can you explain this vulnerability to me?
[{'type': 'paragraph', 'content': "CVE-2026-4742 is a vulnerability in the visualfc liteide project related to inconsistent interpretation of HTTP requests, specifically in the http_parser.C module. The issue arises from improper handling of the Transfer-Encoding HTTP header, where the parser incorrectly allows the 'chunked' encoding flag to persist across multiple Transfer-Encoding headers even when it should not. This flaw can cause the HTTP parser to misinterpret the transfer encoding of HTTP messages, leading to potential security risks."}, {'type': 'paragraph', 'content': 'The vulnerability is a form of HTTP Request/Response Smuggling, where the server and intermediary devices may have different interpretations of the HTTP message boundaries, enabling attackers to bypass security controls or inject malicious requests.'}] [1]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': 'This vulnerability involves improper handling of multiple Transfer-Encoding HTTP headers, specifically the chunked encoding flag. Detection can focus on identifying HTTP requests or responses that contain multiple Transfer-Encoding headers or malformed Transfer-Encoding values.'}, {'type': 'paragraph', 'content': 'You can use network traffic inspection tools like tcpdump or Wireshark to capture HTTP traffic and filter for suspicious Transfer-Encoding headers.'}, {'type': 'list_item', 'content': "Use tcpdump to capture HTTP traffic: tcpdump -i <interface> -A 'tcp port 80 or 443'"}, {'type': 'list_item', 'content': 'Use grep or similar tools to search for multiple Transfer-Encoding headers in captured HTTP requests or responses.'}, {'type': 'list_item', 'content': 'Use curl or similar HTTP clients to manually test servers by sending crafted HTTP requests with multiple Transfer-Encoding headers to observe server behavior.'}] [1]
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation step is to update liteide to version x38.4 or later, where the vulnerability has been fixed by applying the security patch that correctly handles multiple Transfer-Encoding headers.
If updating is not immediately possible, consider implementing network-level protections such as web application firewalls (WAFs) that can detect and block HTTP requests with multiple or malformed Transfer-Encoding headers.
Review and monitor HTTP traffic for suspicious Transfer-Encoding header usage to prevent exploitation.