Vulnerability · Published Mar 2, 2026 · Assigned by GitHub_M

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

High 7.6

In plain English

A high-severity security flaw in textream from f. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).

Severity (CVSS 3.1)7.6High

Exploit odds (30 days)0.2%top 93.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
f	textream	< 1.5.1

Weakness: CWE-346 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L

References

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