CVE-2026-28403 Textream Cross-Site WebSocket Hijacking (CSWSH) vulnerability
A malicious web page can hijack the local WebSocket connection to remotely control teleprompter content in Textream for macOS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-28403?
CVE-2026-28403 is a high-severity vulnerability in f textream, published on 2 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-346
Which versions are affected by CVE-2026-28403?
It affects 1 product.
Products include Fka Textream.
How do I fix CVE-2026-28403?
No fix has been published for CVE-2026-28403 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-28403 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28403 exists.
Other vulnerabilities in f textream
Sources
Also known as GHSA-wr3v-x247-337w.