The vulnerability occurs when the toolkit validates remote media URLs using a parser that treats backslashes differently than the HTTP client, allowing a URL that appears to point to a public hostname to resolve to an internal host after the request is sent. This bypasses the non‑global address checks and permits an attacker to cause the application to access internal HTTP services, potentially exposing sensitive data.

InternLM lmdeploy products from version 0.12.3 up to, but not including, version 0.15.0 are affected. The issue was fixed in release 0.15.0.

With a CVSS score of 7.5, the vulnerability is considered high severity, yet EPSS information is not available and it is not listed in the CISA KEV catalog. The likely attack path involves an attacker‑controlled media URL that the application accepts; the URL is then interpreted by the HTTP client and resolved to an internal host, enabling unauthorized data exfiltration from internal services.