CVE-2026-58016

A flaw was found in GLib. A state confusion issue exists in g_dbus_node_info_new_for_xml() in the gio/gdbusintrospection.c file when processing malformed D-Bus introspection XML, specifically with a node element nested within other elements like method, signal, property or arg. This issue can cause an unsigned integer overflow and lead to an out-of-bounds read, resulting in a denial of service.

Any applications processing D-Bus introspection XML input from untrusted sources with g_dbus_node_info_new_for_xml() are vulnerable to this issue. In GLib itself, the gdbus command line tool is the primary vector for local exploitation. However, other applications using the vulnerable function may process untrusted input in a way that allows a remote attacker to trigger this flaw. This vulnerability can cause an unsigned integer overflow and lead to an out-of-bounds read, resulting in a denial of service. As this vulnerability allows a remote attacker to cause a denial of service, it has been rated with an important severity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, implement input validation to sanitize untrusted D-Bus introspection XML, specifically rejecting malformed structures such as <node> elements improperly nested within <method>, <signal>, <property> or <arg> elements before calling g_dbus_node_info_new_for_xml(). Alternatively, restricting the application to only process XML input from trusted, authenticated sources will completely neutralize this issue.