CVE-2026-110600

xlsxio through 0.2.37 contains a NULL pointer dereference vulnerability in main sheet get sheetfile expat callback element start() in lib/xlsxio read.c that allows attackers to crash applications via crafted files. Attackers can supply a .xlsx file whose workbook.xml.rels contains a worksheet Relationship lacking an Id attribute, crashing the process when xlsxioread sheet open() is called.