CVE-2020-26574: Leostream Connection Broker

Critical severity, CVSS 9.6. EPSS: 2.1% chance of exploitation in the next 30 days.

Leostream Connection Broker 8.2.x is affected by stored XSS. An unauthenticated attacker can inject arbitrary JavaScript code via the webquery.pl User-Agent HTTP header. It is rendered by the admins the next time they log in. The JavaScript injected can be used to force the admin to upload a malicious Perl script that will be executed as root via libMisc::browser_client. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Affected products

• Leostream Connection Broker: from 8.2.15, up to and including 8.2.73

Published 2020-10-06. Last modified 2026-06-17.