A heap use-after-free flaw was found in Gnumeric's workbook XML parser. A malformed SheetObjectComponent element can cause the parser to release a sheet-object component and later pass the freed object to sheet_object_component_set_component(). When a user opens a crafted Gnumeric workbook, the stale object is dereferenced during XML parsing, causing Gnumeric to crash. The issue was reproduced in the 1.12.61 release and an AddressSanitizer-instrumented development build; it was also present in source reported as version 1.11.0 and later. The available proof of concept demonstrates a denial of service only. No code execution, information disclosure, or data-integrity impact has been demonstrated. A patch was available, but no fixed release had been identified at the time of reporting.