What Browsers Do in the Shaders: A Measurement Study of WebGPU Privacy

Computer Science > Cryptography and Security [Submitted on 24 Jun 2026] What Browsers Do in the Shaders: A Measurement Study of WebGPU Privacy Igor Santos-Grueiro WebGPU lets ordinary web pages run GPU workloads through a validated programming model. Validation protects memory safety, but shared browser, driver, OS, and GPU state can still expose privacy-relevant signals. We present WGPULens, a framework for measuring those signals across controlled scenarios, browser-native co-residency, a participant field study, public page loads, and mitigation policies. Our framework separates measurements: controlled scenarios support leakage, boundary, and mitigation claims; participant runs support deployment, compatibility, and fingerprintability; and a Tranco crawl measures WebGPU exposure in real-world pages. Our controlled results identify persistent pipeline compilation state as the clearest surface. Cold/warm pipeline probes reveal prior compilation state across selected origin, profile, and browser placements. Controlled browser/native experiments also show native GPU activity can be inferred from browser-visible observables under labeled workloads. Other resource probes provide weaker positive results and negative controls. The participant field study shows active WebGPU behavior is highly distinctive within the sample, with deterministic components stable within runs and lower exact stability across repeated visits. A page-load crawl finds WebGPU use mainly as adapter probing and static support code, with no observed page-load shader, pipeline, queue, query, or map activity. Mitigation pilots identify source-level key separation as a proxy for evaluating pipeline-cache partitioning. Overall, WGPULens shows that WebGPU privacy analysis must be surface-specific: browsers need to measure which GPU state crosses which boundary, which browser-visible signals reveal it, and what the corresponding mitigations cost. Comments: 20 pages Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2606.26412 [cs.CR]   (or arXiv:2606.26412v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2606.26412 Focus to learn more Submission history From: Igor Santos-Grueiro [view email] [v1] Wed, 24 Jun 2026 22:11:06 UTC (42 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-06 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)