{"cve":"CVE-2011-1756","nvd":{"published":"2011-06-21T02:52:43.607","modified":"2026-06-16T23:29:58.023","status":"Modified","description":"modules/xmpp/serv_xmpp.c in Citadel 7.86 and earlier does not properly detect recursion during entity expansion, which allows remote attackers to cause a denial of service (memory and CPU consumption) via a crafted XML document containing a large number of nested entity references, a similar issue to CVE-2003-1564.","cvss_v4":null,"cvss_v3":null,"cwes":["CWE-399"],"references":["http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=27c991cc2059f5530d3d4e9689dc976b745f5b0c","http://code.citadel.org/cgit.cgi/git.citadel.org/commit/?id=95040add546a705cc2d1d8f16293141f9f9845a6","http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.37-8+lenny1/changelog","http://packages.debian.org/changelogs/pool/main/c/citadel/citadel_7.83-2squeeze2/changelog","http://secunia.com/advisories/44788"],"products":["citadel:citadel"],"source":"nvd","synced_at":"2026-10-19T19:58:50.521460154+00:00"},"epss":{"cve":"CVE-2011-1756","score":0.0266,"percentile":0.85692,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}