GPUThor reports the first Rowhammer exploits against ECC-protected NVIDIA GPUs

Sources: primary, discussion
Summary: The authors reverse engineer memory-access coalescing to hammer aggressor rows harder than decoy rows and stretch hammering patterns across refresh intervals, reporting 500 to 23,500 times more bit flips than prior GPU Rowhammer work, which produced tens to hundreds. They state this induces uncorrectable double and triple bit flips on A4000, A4500, A5000 and A6000 parts. The paper states it will appear at CCS 2026, no CVE is assigned, and NVIDIA has published nothing on it.
Why it matters: Denial of service and privilege escalation become practical on shared GPU hosts where ECC was the assumed mitigation.
Follow-up: Track an NVIDIA statement, a CVE assignment, and any independent reproduction on the named parts.