Threats affecting pkg:github/libxls/libxls

CVE-2026-79592 is a high-severity out-of-bounds read vulnerability in libxls versions prior to 1.6.3. It arises from insufficient validation of OLE summary offsets in the xls_dumpSummary() function, allowing unauthorized reading of memory contents and potential exposure of sensitive information.

CVE-2026-79591 is a high-severity vulnerability in libxls version 1.6.3 and earlier. It involves a heap-buffer-overflow and use-after-free in the xls_getCSS() function caused by insufficient validation of a file-controlled font index. This flaw can lead to high impact on confidentiality, integrity, and availability if exploited. No patch or official fix information is currently provided.

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

CVE-2023-38852 is a buffer overflow vulnerability in libxls version 1.6.2. It occurs in the unicode_decode_wcstombs function within xlstool.c at line 266. This flaw allows a remote attacker to execute arbitrary code or cause a denial of service by crafting a malicious XLS file.