JPEG XL (aka jpeg-xl) through 0.3.2 allows writable memory corruption.

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).

libjxl v0.5.0 is affected by a Assertion failed issue in lib/jxl/image.cc jxl::PlaneBase::PlaneBase(). When encoding a malicous GIF file using cjxl, an attacker can trigger a denial of service.

libjxl v0.3.7 is affected by a Divide By Zero in issue in lib/extras/codecapng.cc jxl::DecodeImageAPNG(). When encoding a malicous APNG file using cjxl, an attacker can trigger a denial of service.

libjxl 0.6.1 has an assertion failure in LowMemoryRenderPipeline::Init() in renderpipeline/lowmemoryrenderpipeline.cc.

libjxl b02d6b9, as used in libvips 8.11 through 8.11.2 and other products, has an out-of-bounds write in jxl::ModularFrameDecoder::DecodeGroup (called from jxl::FrameDecoder::ProcessACGroup and jxl::ThreadPool::RunCallState<jxl::FrameDecoder::ProcessSections).

Invalid JPEG XL images using libjxl can cause an out of bounds access on a std::vector<std::vector<T>> when rendering splines. The OOB read access can either lead to a segfault, or rendering splines based on other process memory. It is recommended to upgrade past 0.6.0 or patch with https://github.com/libjxl/libjxl/pull/757

A specially-crafted file can cause libjxl's decoder to read pixel data from uninitialized (but allocated) memory.

This can be done by causing the decoder to reference an outside-image-bound area in a subsequent patches. An incorrect optimization causes the decoder to omit populating those areas.