PYSEC-2026-363 Jupyter Enterprise Gateway: ContainerProcessProxy._enforce_prohibited_ids Bypass

Summary Jupyter Enterprise Gateway has a prohibited UID and GID feature that by default prevents launching kernels with UID or GID 0 root. This can be bypassed. It is possible to launch kernels with a prohibited UID and/or GID by using a specially crafted KERNELUID or KERNELGID value. The feature...