Multiple security vulnerabilities have been identified in the Qt 6 QtBase modules, including null pointer dereference, out-of-bounds reads, and denial-of-service conditions triggered by specially crafted inputs. These affect components such as QCborValue JSON conversion, QAuthenticator NTLM authentication, QDomDocument XML parsing, and HTTP Cache-Control header parsing. The vulnerabilities can lead to application crashes, information disclosure, or denial of service. A security update fixing these issues is available in version 6.5.2-18.oe2403sp3.