A NULL pointer dereference vulnerability exists in the xpath.c:xmlXPathCompOpEval function of libxml2 through 2.9.8 when parsing an invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case. Applications processing untrusted XSL format inputs with the use of the libxml2 library may be vulnerable to a denial of service attack due to a crash of the application. A null pointer dereference vulnerability exists in the xpath.c:xmlXPathCompOpEval function of libxml2 when parsing invalid XPath expression. Applications processing untrusted XSL format inputs with the use of libxml2 library may be vulnerable to denial of service attack due to crash of the application. Use after free in libxml2 before 2.9.5, as used in Google Chrome prior to 63.0.3239.84 and other products, allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. A use-after-free flaw was found in the libxml2 library. An attacker could use this flaw to cause an application linked against libxml2 to crash when parsing a specially crafted XML file. The xz_decomp function in xzlib.c in libxml2 2.9.1 does not properly detect compression errors, which allows context-dependent attackers to cause a denial of service via crafted XML data. A denial of service flaw was found in libxml2. A remote attacker could provide a specially crafted XML or HTML file that, when processed by an application using libxml2, would cause that application to crash. libxml2 2.9.8, if --with-lzma is used, allows remote attackers to cause a denial of service via a crafted XML file that triggers LZMA_MEMLIMIT_ERROR, as demonstrated by xmllint, a different vulnerability than CVE-2015-8035 and CVE-2018-9251 . The xz_head function in xzlib.c in libxml2 before 2.9.6 allows remote attackers to cause a denial of service via a crafted LZMA file, because the decoder functionality does not restrict memory usage to what is required for a legitimate file. Use-after-free vulnerability in libxml2 through 2.9.4, as used in Google Chrome before 52.0.2743.82, allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors related to the XPointer range-to function