CVE-2026-28403
📋 TL;DR
Textream macOS teleprompter app versions before 1.5.1 have a WebSocket server that doesn't validate the Origin header, allowing malicious web pages to connect and remotely control teleprompter content. This affects macOS users running vulnerable Textream versions who visit compromised websites while the app is running.
💻 Affected Systems
- Textream
📦 What is this software?
Textream by Textream
⚠️ Risk & Real-World Impact
Worst Case
An attacker could completely control teleprompter content, potentially displaying malicious or misleading information during live broadcasts or recordings.
Likely Case
Malicious websites could manipulate teleprompter text to display inappropriate content or disrupt presentations.
If Mitigated
With proper origin validation, only legitimate connections from the Textream app itself can control the teleprompter.
🎯 Exploit Status
Exploitation requires JavaScript execution in browser and vulnerable Textream instance running
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.1
Vendor Advisory: https://github.com/f/textream/security/advisories/GHSA-wr3v-x247-337w
Restart Required: Yes
Instructions:
1. Download Textream 1.5.1 or newer from official source
2. Install the update
3. Restart Textream application
🔧 Temporary Workarounds
Disable Textream when not in use
allClose Textream application when not actively using teleprompter functionality
Use browser extensions to block WebSocket connections
allConfigure browser security extensions to block WebSocket connections to localhost
🧯 If You Can't Patch
- Only run Textream when actively needed and close it immediately after use
- Use separate browser profiles/sessions for general browsing vs teleprompter work
🔍 How to Verify
Check if Vulnerable:
Check Textream version in application settings or About dialogCheck Version:
Open Textream → Click 'Textream' menu → Select 'About Textream'Verify Fix Applied:
Verify version is 1.5.1 or higher and test that WebSocket connections from unauthorized origins are rejected📡 Detection & Monitoring
Log Indicators:
- Unexpected WebSocket connection attempts to localhost ports
- Unusual DirectorCommand payloads in application logs
Network Indicators:
- WebSocket traffic from browser processes to localhost high-numbered ports
- Unexpected DirectorCommand patterns in network captures
SIEM Query:
process:chrome.exe OR process:firefox.exe AND destination_port:>8000 AND protocol:websocket