A vulnerability in the Extensible Messaging and Presence Protocol (XMPP) service of Cisco Unified Contact Center Express (UCCx) could allow an unauthenticated, remote attacker to masquerade as a legitimate user, aka a Clear Text Authentication Vulnerability. More Information: CSCuw86638. Known Affected Releases: 10.6(1). Known Fixed Releases: 11.5(1.10000.61).