The vulnerability allows any unauthenticated remote attacker to trigger a denial‑of‑service by sending oversized or compressed JSON or URL‑encoded request bodies up to 500 MB. The body‑parser middleware processes these payloads before authentication or whitelist checks, meaning the application will consume CPU and memory while parsing the data, ultimately exhausting server resources and bringing the service down. This is a classic case of an unvalidated input size weakness, mapped to CWE‑400.

Versions 1.12.13 through 1.19.0 of SillyTavern (Sil­lyTavern SillyTavern) are affected. The issue resides in the server’s body‑parsing logic, which exists in each deployment of these releases.

The CVSS score of 8.2 indicates a high‑severity exploit. Attackers can trigger the flaw remotely without authentication by accessing the public API endpoint and sending a large or compressed payload. The EPSS score is not reported, but the simplicity of the attack vector and lack of mitigation in the affected versions imply a relatively high likelihood of exploitation for an active attacker. The vulnerability is not listed in the CISA KEV catalog, and no official workaround is available, so deployment of a patched version or alternative mitigations is critical.