CVE-2026-111987: Cross Site Scripting in AUTOMATIC1111 stable-diffusion-webui

This vulnerability affects AUTOMATIC1111 stable-diffusion-webui up to version 1.10.1 in the read_metadata_from_safetensors function of modules/sd_models.py, specifically in the Extra-Networks Card Builder component. An attacker can manipulate the __metadata__.sshs_model_hash argument to execute cross-site scripting attacks remotely. The vulnerability has a CVSS 4.0 score of 5.3 (medium severity) with network attack vector, low attack complexity, no privileges required, user interaction required, and partial impact on integrity. Public exploit code exists, but no vendor response or patch has been published yet.

Successful exploitation allows an attacker to perform cross-site scripting attacks remotely, potentially leading to the execution of arbitrary scripts in the context of the affected web interface. This can result in user session hijacking, defacement, or other malicious actions limited to the scope of the web UI. The vulnerability does not require privileges or authentication but does require user interaction.

No official fix or patch is currently available as the vendor has not responded to the issue report. Users should exercise caution when processing untrusted safetensors metadata and consider restricting access to the affected component until a patch is released. Monitor the vendor's channels for updates and apply any forthcoming official fixes promptly.