CVE-2026-26824: Libxls Project Libxls

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

libxls through version 1.6.3 contains a use of uninitialized memory vulnerability in the OLE container parser. Memory allocated for the Master Sector Allocation Table (MSAT) in read_MSAT() is not fully initialized before being consumed by ole2_validate_sector_chain(), which may result in application crashes or potential information disclosure when processing a crafted XLS file

Affected products

• Libxls Project Libxls: up to and including 1.6.3

Published 2026-06-03. Last modified 2026-09-23.