In Mesa before 25.3.6 and 26 before 26.0.1, out-of-bounds memory access can occur in WebGPU because the amount of to-be-allocated data depends on an untrusted party, and is then used for alloca.
An exploitable shared memory permissions vulnerability exists in the functionality of X11 Mesa 3D Graphics Library 19.1.2. An attacker can access the shared memory without any specific permissions to trigger this vulnerability.