{"data":{"id":"9089a56c-f332-4a8e-98ee-de23eb982ef1","title":"How Much Can Tool Calls Reveal About You? Privacy Leakage from Tool-Call Traces","summary":"Researchers study whether observers can infer user attributes from MCP tool-call traces alone, without access to user conversations. They introduce PrivacyTrace, a benchmark of 1,000 synthetic user profiles and 4,000 agent trajectories across four domains, built with real MCP tools from 25 servers. Four LLM attackers reach a 26.25% attack success rate for profile inference, compared with 17.97% from prior-based guessing, with tool arguments and returned results as the main evidence and cross-session trace linking amplifying the risk.","solution":"N/A -- no mitigation discussed in source.","labels":["security","privacy","research"],"sourceUrl":"https://arxiv.org/abs/2610.41885v1","publishedAt":"2026-10-30T15:30:23.000Z","cveId":null,"cweIds":null,"cvssScore":null,"cvssSeverity":null,"severity":"info","attackType":["data_extraction","pii_leakage"],"issueType":"research","affectedPackages":null,"affectedPackageNames":null,"affectedPackageRefs":null,"affectedVendors":[],"affectedVendorsRaw":["Model Context Protocol (MCP)","LLM-based agents"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":null,"epssScore":null,"epssCheckedAt":null,"kevDateAdded":null,"advisoryAliases":null,"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":null,"disclosureDate":"2026-10-30T15:30:23.000Z","fixReleasedAt":null,"daysToFix":null,"fixCheckedAt":null,"capecIds":null,"crossRefCount":0,"attackSophistication":"moderate","impactType":["confidentiality"],"aiComponentTargeted":"agent","llmSpecific":true,"classifierConfidence":0.93,"researchCategory":"preprint","atlasIds":null}}