A flaw was found in GIMP's GIMPressionist plug-in. When loading a preset file, presets.c parses an attacker-controlled index with atoi() in set_orient_vector() and set_size_vector() and uses it to write into pcvals.orient_vectors[] and pcvals.size_vectors[] without checking that the index is within the fixed array bounds (MAXORIENTVECT and MAXSIZEVECT, 50 entries each). A crafted preset with an out-of-range or negative index causes writes past those arrays, corrupting memory. This issue can be triggered by convincing a user to load a specially crafted GIMPressionist preset, potentially leading to a crash or arbitrary code execution in the context of the user running GIMP. This is distinct from CVE-2026-90947, which addressed a similar missing bound check in the Lighting Effects plug-in. The issue is present in GIMP 3.2.6; a bounds check was added on the main branch.