ComfyUI, a modular diffusion model GUI and API, had a path traversal vulnerability in nodes that load images and media. The flaw allows an attacker to craft a POST request to the /prompt API with a malicious LoadImage or sibling node, bypassing the normal directory validation. This leads to arbitrary file existence checks and the ability to exfiltrate image‑format files from the host system, compromising confidentiality and potentially integrity of stored data. The weakness is a classic path traversal issue (CWE‑22).

The vulnerability affects all installations of ComfyUI prior to version 0.28.0. Products from the Comfy‑Org team, including LoadImage, LoadImageMask, LoadImageOutput, LoadAudio, LoadLatent, LoadVideo, and Load3D nodes, are impacted. Users running any earlier release are at risk.

The CVSS score of 7.5 indicates a high severity. The EPSS score is <1%, indicating a very low probability of exploitation but still possible. The flaw is exploitable over the network through an unauthenticated HTTP POST to the /prompt endpoint. Because the issue is not listed in the CISA KEV catalog, it has not yet been widely reported as exploited in the wild, though the attack path is straightforward and can be automated. Patch status is critical; applying the 0.28.0 release removes the containment check and mitigates the risk.