【中文导读】该 CVE 涉及空指针（高危风险）。具体受影响产品、版本和修复方案以 NVD/厂商公告为准。 【原始描述】A null pointer dereference occurs in the function break_word_for_overflow_wrap() in MuPDF 1.26.4 when rendering a malformed EPUB document. Specifically, the function calls fz_html_split_flow() to split a FLOW_WORD node, but does not check if node->next is valid before accessing node->next->overflow_wrap, resulting in a crash if the split fails or returns a partial node chain.