CVE-2026-1837

A specially-crafted file can cause libjxl's decoder to write pixel data to uninitialized unallocated memory. Soon after that data from another uninitialized unallocated region is copied to pixel data. This can be done by requesting color transformation of grayscale images to another grayscale color space. Buffers allocated for 1-float-per-pixel are used as if they are allocated for 3-float-per-pixel. That happens only if LCMS2 is used as CMS engine. There is another CMS engine available (selected by build flags).

A specially-crafted file can cause libjxl's decoder to write pixel data to uninitialized unallocated memory. Soon after that data from another uninitialized unallocated region is copied to pixel data. This can be done by requesting color transformation of grayscale images to another grayscale color space. Buffers allocated for 1-float-per-pixel are used as if they are allocated for 3-float-per-pixel. That happens only if LCMS2 is used as CMS engine. There is another CMS engine available (selected by build flags).

Un archivo especialmente diseñado puede provocar que el decodificador de libjxl escriba datos de píxeles en memoria no asignada no inicializada. Poco después, datos de otra región no asignada no inicializada se copian a los datos de píxeles. Esto puede hacerse al solicitar una transformación de color de imágenes en escala de grises a otro espacio de color en escala de grises. Búferes asignados para 1 flotante por píxel se utilizan como si estuvieran asignados para 3 flotantes por píxel. Esto ocurre solo si se utiliza LCMS2 como motor CMS. Hay otro motor CMS disponible (seleccionado mediante indicadores de compilación).