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GPUThor: Amplifying Rowhammer Attacks via Non-Uniform Patterns to Exploit ECC-Protected GPUs

GPUThor uses non-uniform hammering to amplify Rowhammer on NVIDIA GPUs, achieving 500X-23,500X more bit flips and first exploits of ECC-protected GPUs.

GPUThor is a Rowhammer attack on NVIDIA GPUs that reverse-engineers memory-access coalescing behavior to enable non-uniform hammering patterns activating aggressor rows more intensely than decoy rows. By identifying refresh instances where in-DRAM mitigations apply, it constructs longer patterns that escape mitigation across refresh intervals. It yields 500X to 23,500X more bit flips than prior GPU Rowhammer attacks across NVIDIA A4000, A4500, A5000, and A6000 GPUs, and enables the first Rowhammer exploits on ECC-protected GPUs via uncorrectable double and triple bit flips, making denial-of-service and privilege-escalation attacks practical.

arXiv cs.CR · 1d agoResearch

How well do agents use test/verification techniques?

Dan Luu's eval finds coding-agent testing instructions (TDD, formal methods, PBT, skills) mostly fail to beat defaults on Zstd implementation correctness.

The author ran 26 prompt conditions plus 4 skills on a Zstd-in-Rust implementation eval using codex with GPT-5.6, testing TDD, fuzzing, property-based testing, formal methods (Lean 4, TLA+, Verus, Kani, SMT solvers) and community skills. Nothing dramatically outperformed the default no-instruction condition, which did above average; at xhigh effort, fuzzing and PBT conditions did slightly better than formal methods. Pre-registered predictions included TDD underperforming and popular test skills (ECC, Hegel, Trail of Bits) not outperforming. Results are averages of 80 runs per condition plotted against cost.

Rogue ScreenConnect Installations Across Unrelated Hosts Suggest Worm-Like Activity

Huntress observed rogue ScreenConnect deployments with worm-like VBScript propagation across unrelated organizations, prompting a ConnectWise advisory on file transfer behavior.

Huntress identified multiple incidents in late August 2026 where social engineering led to rogue ScreenConnect remote access clients deployed on victim machines, which then spawned wscript.exe to run four VBScript payloads (1.vbs through 4.vbs) for profiling, telemetry collection, and persistence via a WindowsServiceHost Run key. Modified ScreenConnect clients propagated the VBScript chain to connected endpoints, creating worm-like spread. ConnectWise published an advisory on September 3, 2026, confirming an issue affecting file transfer behavior in both cloud and on-premises ScreenConnect deployments, with a CVE and fix expected within the week; partners were advised to review and disable TransferFiles permissions in the interim.

Huntress · 13d agoExploit / PoC in the wild1

Quantization-Aware Healing: a compressed, 4-bit model that outperforms its full-precision original

Multiverse Computing details quantization-aware healing, producing a 4-bit compressed model that reportedly outperforms its full-precision original.

A Hugging Face blog post by Multiverse Computing's CAI team introduces quantization-aware healing for compressed models. The post claims the resulting 4-bit model outperforms the original full-precision model. No additional details or benchmarks were available in the provided text.

Hugging Face Blog · 22d agoAI research

Cloudflare Workers Spectre Attack Leaks JWT From Co

Researchers demonstrated a remote Spectre attack leaking a JWT between co-located Cloudflare Workers at 12 bits per second, 360x the 2021 rate.

Security researchers showed a remote Spectre attack against Cloudflare Workers that leaked a JWT from a co-located Worker at up to 12 bits per second with 99.16% accuracy, 360 times the 2021 demonstration rate. The attack exploited weaknesses in DyPrIs dynamic process isolation, where long-lived Durable Object invocations could run before isolation and WebSocket-heavy I/O suppressed the branch-misprediction signal. Cloudflare deployed improved DyPrIs, the V8 Sandbox, and MPK-based in-process isolation, and found no indicators of active exploitation over three years.

The Hacker News · 27d agoVulnerability