CVE-2026-56412 libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219. Information published. EPSS 0.00 CVE-2026-50219 CVE-2026-56412 libexpat US Microsoft Security · 5. 6. 10:02