In xinclude in libxml2 before 2.15.4, xmlXIncludeProcess and xmlXIncludeProcessTree do not propagate parseFlags. This has security relevance for, for example, the XML_PARSE_NONET flag, if (without it) a custom resource loader accesses the internet and triggers XML external entity injection, SSRF, or a denial of service (e.g., for an attacker-controlled internet resource that is intentionally slow).
Analyzing vulnerability vectors…