xmlregexp in libxml2 before 2.15.4 has a NULL pointer dereference in xmlRegNewParserCtxt after a strdup failure, i.e., it does not calculate a string length after NULL checking.

A vulnerability was found in libxml2 up to 2.14.5. It has been declared as problematic. This vulnerability affects the function xmlParseSGMLCatalog of the component xmlcatalog. The manipulation leads to uncontrolled recursion. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used. The real existence of this vulnerability is still doubted at the moment. The code maintainer explains, that "[t]he issue can only be triggered with untrusted SGML catalogs and it makes absolutely no sense to use untrusted catalogs. I also doubt that anyone is still using SGML catalogs at all."

Stack-based buffer overflow vulnerability in the interactive shell of the xmllint tool in libxml2. The issue is caused by an unsafe use of strcpy() when processing user-supplied command-line input. When an attacker passes an overly long argument to any shell command (e.g., exit, cat, etc.), the input exceeds the fixed-size stack buffer, resulting in a crash or potentially arbitrary code execution on systems lacking stack protections. This vulnerability affects only the interactive shell and requires that an attacker can influence or control the command input to xmllint, which is uncommon in typical deployments.