CVE-2026-108559

A reflected cross-site scripting vulnerability in the iframe invocation options of Revive Adserver 6.0.8 and earlier allows an unauthenticated attacker to execute JavaScript in an authenticated user's browser by persuading them to visit a crafted URL. When generating invocation tags for an any-size zone, the frame_width and frame_height request parameters are included in HTML attributes without appropriate encoding. The issue is fixed in Revive Adserver 6.0.9 by HTML-encoding the affected values in the invocation-option form fields.