The xmlStringGetNodeList function in tree.c in libxml2 2.9.3 and earlier, when used in recovery mode, allows context-dependent attackers to cause a denial of service (infinite recursion, stack consumption, and application crash) via a crafted XML document.
The xsl_ext_function_php function in ext/xsl/xsltprocessor.c in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13, when libxml2 before 2.9.2 is used, does not consider the possibility of a NULL valuePop return value before proceeding with a free operation after the principal argument loop, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted XML document, a different vulnerability than CVE-2015-6837.
The xsl_ext_function_php function in ext/xsl/xsltprocessor.c in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13, when libxml2 before 2.9.2 is used, does not consider the possibility of a NULL valuePop return value before proceeding with a free operation during initial error checking, which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted XML document, a different vulnerability than CVE-2015-6838.
dict.c in libxml2 allows remote attackers to cause a denial of service (heap-based buffer over-read and application crash) via an unexpected character immediately after the "<!DOCTYPE html" substring in a crafted HTML document.
The htmlParseComment function in HTMLparser.c in libxml2 allows attackers to obtain sensitive information, cause a denial of service (out-of-bounds heap memory access and application crash), or possibly have unspecified other impact via an unclosed HTML comment.
The xmlNextChar function in libxml2 before 2.9.4 allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted XML document.
The htmlParseNameComplex function in HTMLparser.c in libxml2 allows attackers to cause a denial of service (out-of-bounds read) via a crafted XML document.
The xmlParseXMLDecl function in parser.c in libxml2 before 2.9.3 allows context-dependent attackers to obtain sensitive information via an (1) unterminated encoding value or (2) incomplete XML declaration in XML data, which triggers an out-of-bounds heap read.
The xmlSAX2TextNode function in SAX2.c in the push interface in the HTML parser in libxml2 before 2.9.3 allows context-dependent attackers to cause a denial of service (stack-based buffer over-read and application crash) or obtain sensitive information via crafted XML data.
The xmlNextChar function in libxml2 2.9.2 does not properly check the state, which allows context-dependent attackers to cause a denial of service (heap-based buffer over-read and application crash) or obtain sensitive information via crafted XML data.