CVE-2011-1756: modules/xmpp/serv_xmpp.c in Citadel 7.86 and earlier does not properly detect recursion during entity expan...

Security readout for executives and security teams

CVE-2011-1756 is a denial-of-service issue in Citadel 7.86 and earlier. A remote attacker could send specially crafted XML to the XMPP service, causing excessive memory and CPU use. The business impact is service disruption, not documented data theft or code execution in the provided sources. Exposure is most likely where Citadel 7.86 or earlier is deployed and its XMPP component accepts remote XML input. Internet-facing or untrusted-network XMPP services carry higher operational risk. The source bundle does not identify other affected products or precise package ranges beyond Citadel and Debian security packaging. Prioritize remediation for internet-facing or business-critical Citadel servers. This is not evidenced as code execution or data compromise, but it can interrupt messaging or collaboration services. Legacy deployments should be upgraded or isolated promptly because the affected versions are old and security support may be limited. Mitigation focus: Upgrade Citadel using vendor or distribution security updates covering CVE-2011-1756.; Apply relevant Debian DSA-2250 packages where Debian Citadel packages are used.; Disable or restrict XMPP exposure if the service is not required..

Prepared

Jun 28, 2026, 00:52 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.