What’s Vulnerable › Vulnerabilities

CVE-2026-28403: Textream Cross-Site WebSocket Hijacking (CSWSH) vulnerability

• Severity: high (CVSS 7.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-02 · updated 2026-06-17
• Weakness: CWE-346

Description

Textream is a free macOS teleprompter app. Prior to version 1.5.1, the `DirectorServer` WebSocket server (`ws://127.0.0.1:<httpPort+1>`) accepts connections from any origin without validating the HTTP `Origin` header during the WebSocket handshake. A malicious web page visited in the same browser session can silently connect to the local WebSocket server and send arbitrary `DirectorCommand` payloads, allowing full remote control of the teleprompter content. Version 1.5.1 fixes the issue.

Affected products

• f textream: before 1.5.1 — fixed in 1.5.1

How to fix

Upgrade to a fixed version: f textream 1.5.1. Check the vendor advisory for mitigations.

References

• https://github.com/f/textream/commit/f5ebad82750b9313386c34af8f0ede50c213a8a0
• https://github.com/f/textream/security/advisories/GHSA-wr3v-x247-337w

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