The vulnerability originates in the curl_cffi Python binding. Versions before 0.15.0 are missing safeguards that block request redirects to internal IP ranges. When an attacker supplies a specially crafted URL, curl_cffi automatically follows the redirect using libcurl, allowing a request to be sent to internal services such as cloud metadata endpoints. The library's TLS impersonation feature can make these internal requests appear as legitimate browser traffic, potentially bypassing network controls. This flaw enables attackers to obtain sensitive internal data or credentials, directly impacting confidentiality and potentially integrity of the system. The weakness is classified as an SSRF, CWE‑918.

Lexiforest’s curl_cffi library is affected. All releases prior to version 0.15.0 are vulnerable. The issue persists in any installation of curl_cffi that relies on default redirect behavior without explicit restrictions, regardless of the Python application using it.

The CVSS score of 8.6 marks the flaw as high severity. No EPSS data is available, so the precise likelihood of exploitation remains unknown, but the lack of restriction on internal redirects and the ability to masquerade traffic suggest that the threat adversary can execute an attack without complex conditions. The flaw is not currently listed in the CISA KEV catalog, indicating no confirmed public exploits yet. Nevertheless, the potential impact warrants prompt mitigation.