The media proxy service in stoatchat processes SVG images and incorrectly resolves <image href> attributes as absolute local filesystem paths when documents are served as image/svg+xml. An attacker can request the proxy endpoint to fetch an SVG file that references locally stored images. Because the proxy reads the referenced file without imposing limits, it can disclose the file contents with re‑encoding and also reveal the existence of files through measurable response‑time differences. A single request can trigger an unbounded amount of local reads, potentially exhausting memory and I/O resources leading to denial of service.

stoatchat stoatchat before version 0.15.5 is affected. The vulnerability is present in all releases earlier than 0.15.5 and has been fixed in 0.15.5 and later releases.

The vulnerability carries a CVSS score of 8.8, indicating high severity. The EPSS score is not available, and the issue is not yet listed in the CISA KEV catalog. An attacker does not need authentication and can exploit the flaw by sending a crafted SVG to the proxy endpoint from a remote location. The lack of input validation and the unlimited file read operation make the attack path straightforward, while the potential denial‑of‑service payload adds further risk. Consequently, the overall exposure is significant for environments running vulnerable stoatchat versions.