Bug 2484545 (CVE-2026-26825)

Summary: CVE-2026-26825 libxls: libxls: Information disclosure via use of uninitialized memory
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: low    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in libxls. This use-of-uninitialized memory vulnerability occurs when the software processes specially crafted XLS files. An attacker could exploit this by providing a malformed XLS file, which may lead to undefined behavior, incorrect parsing logic, or potential information disclosure.
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Bug Depends On: 2484567    
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Description OSIDB Bzimport 2026-06-03 21:01:23 UTC 
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.