CVE-2026-1466
MIME Sniffing Bypass in Jirafeau Enables Cross-Site Scripting
Publication date: 2026-01-28
Last updated on: 2026-02-12
Assigner: GitLab Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| jirafeau | jirafeau | to 4.7.1 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in Jirafeau allows an attacker to bypass the MIME type check that normally prevents browser preview of text files, such as SVG and HTML, which could be exploited for cross-site scripting (XSS). By sending a manipulated HTTP request with an invalid MIME type like 'image.', the browser attempts to auto-detect the MIME type and may incorrectly identify it as SVG, potentially executing malicious JavaScript code. This occurs because MIME sniffing is not properly disabled.
How can this vulnerability impact me? :
The vulnerability can lead to cross-site scripting (XSS) attacks, where malicious JavaScript code is executed in the context of the victim's browser. This can result in unauthorized actions, data theft, or session hijacking. Since the vulnerability allows bypassing MIME type restrictions, it increases the risk of executing harmful scripts when previewing files in the browser.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
You can detect this vulnerability by inspecting HTTP responses from the Jirafeau server to check if the header 'X-Content-Type-Options: nosniff' is missing. For example, use the command: curl -I http://<jirafeau-server>/file to see if the header is present. If the header is absent, the system may be vulnerable to MIME sniffing attacks as described.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, ensure that the HTTP header 'X-Content-Type-Options: nosniff' is sent by the Jirafeau server to disable MIME sniffing. This prevents browsers from automatically detecting MIME types and executing potentially malicious scripts embedded in files. Additionally, verify that MIME type checks are properly enforced and that manipulated MIME types like 'image.' are not accepted for browser preview.