CVE-2026-1466
📋 TL;DR
This vulnerability in Jirafeau allows attackers to bypass MIME type restrictions by sending manipulated HTTP requests with invalid MIME types like 'image'. This enables cross-site scripting (XSS) attacks when browsers automatically detect and render SVG files containing malicious JavaScript. All Jirafeau instances without proper MIME sniffing protection are affected.
💻 Affected Systems
- Jirafeau
📦 What is this software?
Jirafeau by Jirafeau
⚠️ Risk & Real-World Impact
Worst Case
Attackers can execute arbitrary JavaScript in victims' browsers, potentially stealing session cookies, performing actions as authenticated users, or redirecting to malicious sites.
Likely Case
Cross-site scripting attacks leading to session hijacking, credential theft, or defacement of the Jirafeau interface.
If Mitigated
Limited impact with proper Content Security Policy and input validation, though some XSS vectors might still exist.
🎯 Exploit Status
Exploitation requires uploading a malicious SVG file and manipulating the MIME type in the request.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 747afb20bfcff14bb67e40e7035d47a6311ba3e1
Vendor Advisory: https://gitlab.com/jirafeau/Jirafeau/-/commit/747afb20bfcff14bb67e40e7035d47a6311ba3e1
Restart Required: No
Instructions:
1. Update Jirafeau to the latest version or apply commit 747afb20bfcff14bb67e40e7035d47a6311ba3e1
2. Ensure X-Content-Type-Options: nosniff header is being sent
3. Verify MIME type validation is properly implemented
🔧 Temporary Workarounds
Disable file preview functionality
allTemporarily disable browser preview for uploaded files in Jirafeau configuration
Edit Jirafeau configuration to set preview options to disabled
Add X-Content-Type-Options header manually
allConfigure web server to send X-Content-Type-Options: nosniff header for all responses
For Apache: Header set X-Content-Type-Options nosniff
For Nginx: add_header X-Content-Type-Options nosniff;
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) to prevent JavaScript execution from untrusted sources
- Deploy a WAF with XSS protection rules to block malicious requests
🔍 How to Verify
Check if Vulnerable:
Test by uploading an SVG file with JavaScript content and attempting to preview it with a manipulated MIME typeCheck Version:
Check Jirafeau version in admin interface or review git commit historyVerify Fix Applied:
Check that X-Content-Type-Options: nosniff header is present in HTTP responses and test SVG file preview📡 Detection & Monitoring
Log Indicators:
- HTTP requests with manipulated MIME types for SVG files
- Multiple failed preview attempts with unusual MIME types
Network Indicators:
- Requests to file preview endpoints with 'image/' MIME type for non-image files
- Lack of X-Content-Type-Options header in responses
SIEM Query:
http.method:POST AND http.url:*preview* AND http.content_type:image/* AND NOT http.user_agent:*bot*