CVE-2026-6324: libsoup2.4 HTTP Request/Response Smuggling

Vulnerability summary

CVE-2026-6324 is a medium (CVSS 4.8) HTTP Request/Response Smuggling vulnerability in libsoup2.4. EPSS estimates a 0.87% chance of exploitation in the next 30 days, higher than 58.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 29-05-2026
   PublishedVulnerability first disclosed.
2. 29-05-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in libsoup. A remote attacker could exploit an unsigned to signed conversion error in the `soup_body_input_stream_read_chunked()` function by sending a malicious HTTP request. This vulnerability occurs when libsoup operates behind a non-libsoup proxy server or as a proxy in front of a non-libsoup backend server. Successful exploitation can allow an attacker to bypass security controls, poison web caches, or gain unauthorized access.

• CWE-444Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.