OESA-2026-2667

Libsoup is an HTTP library implementation in C. It was originally part of a SOAP (Simple Object Access Protocol) implementation called Soup, but the SOAP and non-SOAP parts have now been split into separate packages.

Security Fix(es):

A flaw was found in libsoup. The SoupWebsocketConnection may accept a large WebSocket message, which may cause libsoup to allocate memory and lead to a denial of service (DoS).(CVE-2025-32049)

A flaw was found in libsoup. The implementation of HTTP range requests is vulnerable to a resource consumption attack. This flaw allows a malicious client to request the same range many times in a single HTTP request, causing the server to use large amounts of memory. This does not allow for a full denial of service.(CVE-2025-32907)

A flaw was found in libsoup's SoupServer. A remote attacker could exploit a use-after-free vulnerability where the soup_server_disconnect() function frees connection objects prematurely, even if a TLS handshake is still pending. If the handshake completes after the connection object has been freed, a dangling pointer is accessed, leading to a server crash and a Denial of Service.(CVE-2026-2436)

A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soupmessageheadersappendcommon() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Content-Length fields. This allows an attacker to send HTTP requests containing multiple Content-Length headers with differing values.(CVE-2026-2708)