UnRTF, a command-line tool for converting Rich Text Format documents to various formats, has a vulnerability (CVE-2026-109831) involving an out-of-bounds write. This flaw can be triggered by opening a specially crafted RTF file, potentially causing a denial-of-service (DoS) condition. The issue affects versions prior to 0.21.13-1.oe2403sp3. A patch is available in version 0.21.13-1.oe2403sp3. The vulnerability has a medium severity rating with a CVSS score of 5.4.