CVE-2021-26236

CVE-2021-26236 is a high-severity stack-based buffer overflow vulnerability affecting FastStone Image Viewer versions up to 7.5. This flaw occurs during the parsing of specially crafted CUR files, specifically within the BITMAPINFOHEADER structure's 'BitCount' field, leading to corruption of the Structured Exception Handler (SEH). Successful exploitation could allow an attacker to achieve arbitrary code execution when a user opens a malicious CUR file. While there is no evidence of active exploitation or publicly available exploit code in Metasploit or ExploitDB, the vulnerability has garnered some community discussion, indicating awareness.