The vulnerability resides in the create_item_html function of the Card Builder component, where a maliciously crafted filename argument is rendered into HTML without proper sanitization. This permits an attacker to inject arbitrary JavaScript that executes in the context of the web UI when a user views the item, potentially enabling credential theft, session hijacking, or defacement. The weakness is classified as CWE‑79 and CWE‑94, indicating unvalidated input and potential code execution via reflective evaluation.

AUTOMATIC1111’s stable‑diffusion‑webui is affected in all releases up to and including 1.10.1. The flaw originates in modules/ui_extra_networks.py and can be triggered by any user who can submit a filename to the Card Builder interface, which is exposed through the web UI of the application.

With a CVSS score of 5.3 the risk is moderate, but the exploit has already been publicly disclosed and can be triggered remotely by supplying a crafted filename via the web interface. The EPSS score is currently not available, and the vulnerability is not listed in CISA’s KEV catalog. Because the attack vector is remote and relies only on user input, an attacker can exercise this flaw from any location with network access to the instance. The impact is limited to the browser context of the victim, but it can be leveraged for wider credential compromise or phishing.