CVE-2026-86140 In libxml2 before 2.15.4, xmlSnprintfElements in valid.c has a strcat stack-based buffer overflow

Description

In libxml2 before 2.15.4, xmlSnprintfElements in valid.c has a strcat stack-based buffer overflow.

Affected products and versions

Product	Affected versions	Fixed in
libxml2 2.15	earliest → < 2.15.4	2.15.4

Other CVEs of libxml2

The 15 CVEs of libxml2 →

CVE-2026-86144 In xinclude in libxml2 before 2.15.4, xmlXIncludeProcess and xmlXIncludeProcessTree do not propagate parseFlags 5.6 Medium CVE-2026-86143 In xmlIO in libxml2 before 2.15.4, an inconsistency in xmlOutputWriteCallback and xmlBufUse causes negative lengths to… 6.9 Medium CVE-2026-86142 In libxml2 before 2.15.4, there is a heap-based buffer overflow in xmlXPtrEvalXPtrPart because of xmlXPtrEval xpointer… 6.9 Medium CVE-2026-86141 xmlregexp in libxml2 before 2.15.4 has a NULL pointer dereference in xmlRegNewParserCtxt after a strdup failure, i.e.,… 2.9 Low