New GPUThor Rowhammer Defeats ECC on NVIDIA RTX A6000 to Gain Host Root Access
Academic researchers have disclosed a Rowhammer attack impacting NVIDIA workstation GPUs with GDDR6 memory that defeats error correction codes (ECC), the mitigation NVIDIA recommends against GPU Rowhammer, and enables denial-of-service (DoS) and privilege escalation to a root shell. Dubbed GPUThor , the attack was developed by researchers at the University of Toronto, who hammered four DRAM banks for 24 hours each on four Ampere-class cards, inducing bit flips on each. The following GPUs were tested and found vulnerable - RTX A6000 (48 GB GDDR6) RTX A5000 (24 GB GDDR6) RTX A4500 (20 GB GDDR6) RTX A4000 (16 GB GDDR6) Mounting the attack requires the ability to launch an unprivileged CUDA kernel on the target GPU, either as a co-tenant on a shared card or as untrusted code on a single-tenant machine. The researchers advise avoiding cross-tenant GPU sharing, monitoring ECC error counters, and restricting untrusted CUDA workloads. "Recently, researchers at the U...
Aug 27, 2026