Description
LibreOffice Calc can import tracked changes from a spreadsheet document. A heap buffer overflow existed when a document reused the same change identifier for two different kinds of change. The importer then treated one change object as a different, larger type and wrote past the end of its allocation. In fixed versions records with a duplicate identifier are rejected.
Problem types
CWE-843 Access of Resource Using Incompatible Type ('Type Confusion')
Product status
25.8 (26.2 series) before < 25.8.7
26.2 (26.2 series) before < 26.2.4
Credits
Anthropic (automated discovery using Claude)
Arthur Chan of Ada Logics (validation and reporting)
References
www.libreoffice.org/...-us/security/advisories/cve-2026-8358