University of Toronto researchers amplify Rowhammer attacks on ECC-protected GPUs

Researchers at the University of Toronto published GPUThor, a high-intensity Rowhammer attack on Nvidia GPUs that uses non-uniform hammering patterns to bypass ECC protection. The method reverse-engineers GPU memory-access coalescing and exploits refresh timing to evade in-DRAM mitigations.

• GPUThor uses non-uniform patterns to activate aggressor rows more intensely than decoy rows
• The attack escapes in-DRAM mitigations by targeting refresh intervals
• It targets Nvidia GPUs with ECC-protected memory
• Preprint arXiv:2609.16546 was published in September 2026