CVE-2026-43904: OpenImageIO: Softimage PIC RLE decoder heap buffer overflow — longCount not clamped to image width

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.18.0 and 3.1.13.0, softimageinput.cpp:469 (mixed RLE) and :345 (pure RLE) do not clamp the run length to remaining scanline width before writing pixels. The raw packet path (line 403) correctly clamps with std::min, but RLE paths skip this check. A crafted .pic file causes heap overflow up to 65535 bytes. This vulnerability is fixed in 3.0.18.0 and 3.1.13.0.