There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. This requires an incorrectly formatted markdown file to be passed to QTextMarkdownImporter to trigger the overflow.This issue affects Qt from 6.8.0 to 6.8.4. Versions up to 6.6.0 are known to be unaffected, and the fix is in 6.8.4 and later.
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().