libsoup, a library used in many Red Hat Enterprise Linux distributions, contains an unsigned to signed conversion error in the function soup_body_input_stream_read_chunked(). When a malicious HTTP request is processed under certain proxy configurations, this error can be exploited for HTTP request smuggling, allowing an attacker to bypass existing security controls, poison web caches or gain unauthorized access. The flaw is a classic example of a type confusion weakness (CWE‑444).

Red Hat Enterprise Linux 6 through 10 are affected because the vulnerability resides in the version of libsoup bundled with these OS releases. Any systems running these distributions with the default libsoup implementation are potentially impacted.

The CVSS score of 4.8 indicates moderate severity, and no publicly available exploit probability metric is reported. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog, which suggests it has not yet been widely exploited. The likely attack vector is a remote attacker sending crafted HTTP requests through a non‑libsoup proxy or positioning libsoup as a proxy in front of a non‑libsoup backend, leading to request smuggling. While the impact is limited to bypassing controls, cache poisoning, or unauthorized access, the absence of a high severity rating and exploit data means the risk is moderate as long as the system topology conforms to the described scenario.