CVE-2026-79591

A stack based buffer overflow vulnerability exists in the xls_getfcell function of libxls 1.3.4. A specially crafted XLS file can cause memory corruption resulting in remote code execution.

An out-of-bounds write vulnerability exists in the read_MSAT function of libxls 1.4. A specially crafted XLS file can cause memory corruption leading to remote code execution.

An out-of-bounds write vulnerability exists in the xls_mergedCells function of libxls 1.4. A specially crafted XLS file can cause memory corruption leading to remote code execution.

An out-of-bounds vulnerability exists in the xls_addCell function of libxls 1.4. A specially crafted XLS file with a formula record can cause memory corruption leading to remote code execution.

An exploitable integer overflow vulnerability exists in the xls_appendSST function of libxls 1.4. A specially crafted XLS file can cause memory corruption resulting in remote code execution.

An out-of-bounds read vulnerability exists in the xls_dumpSummary() function of libxls 1.6.3 due to insufficient validation of file-controlled OLE summary offsets.

A use-of-uninitialized memory vulnerability exists in libxls 1.6.3 when parsing malformed XLS files. The issue is reachable via xls_parseWorkBook() and is triggered by uninitialized heap memory originating from the OLE layer (ole2_read). The flaw is detectable with MemorySanitizer (MSAN) and can lead to undefined behavior, incorrect parsing logic, or potential information disclosure.

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.

Buffer Overflow vulnerability in libxls version 1.6.2 allows a remote attacker to execute arbitrary code and cause a denial of service via a crafted XLS file to the get_string function in xlstool.c:395.

Buffer Overflow vulnerability in libxls version 1.6.2 allows a remote attacker to execute arbitrary code and cause a denial of service via a crafted XLS file to the transcode_latin1_to_utf8 function in xlstool.c:296.