CVE-2026-91059

The GUIX JPEG software decoder enforces no ordering on JPEG markers. A file that places a second SOF0 frame header after SOS re-runs the frame header parser after the output buffer has already been allocated and its geometry latched. The decoder returns GX_SUCCESS and publishes a GX_PIXELMAP whose reported dimensions and data_size exceed the allocation behind it.

Any consumer that trusts the returned structure reads out of bounds, including GUIX's own display drivers, reached through the ordinary draw path.

Reproduces in the shipped default configuration; GX_SOFTWARE_DECODER_SUPPORT is enabled by default.