parser.c in libxml2 before 2.9.2 does not properly prevent entity expansion even when entity substitution has been disabled, which allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted XML document containing a large number of nested entity references, a variant of the "billion laughs" attack.

parser.c in libxml2 before 2.9.0, as used in Google Chrome before 28.0.1500.71 and other products, allows remote attackers to cause a denial of service (out-of-bounds read) via a document that ends abruptly, related to the lack of certain checks for the XML_PARSER_EOF state.

libxml2 2.9.0 and earlier allows context-dependent attackers to cause a denial of service (CPU and memory consumption) via an XML file containing an entity declaration with long replacement text and many references to this entity, aka "internal entity expansion" with linear complexity.

libxml2 before 2.8.0 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted XML data.

Heap-based buffer underflow in the xmlParseAttValueComplex function in parser.c in libxml2 2.9.0 and earlier, as used in Google Chrome before 23.0.1271.91 and other products, allows remote attackers to cause a denial of service or possibly execute arbitrary code via crafted entities in an XML document.

Buffer overflow in the (1) nanohttp or (2) nanoftp modules in XMLSoft Libxml 2 (Libxml2) 2.6.0 through 2.6.5 allow remote attackers to execute arbitrary code via a long URL.