{"id":"CVE-2026-101201","kind":"vulnerability","aliases":["CVE-2026-101201"],"related":[],"title":"Qt: malformed binary JSON header causes out-of-bounds read","description":"A malformed header in the binary file fed to QBinaryJson::fromBinaryData() can cause undefined behaviour because of out-of-bounds read.","summary":"A malformed header in binary data passed to QBinaryJson::fromBinaryData() in Qt triggers an out-of-bounds read, which is undefined behaviour. The sources do not say whether this leads to code execution or only a crash or information leak.","severity":"medium","cvss":4.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["c++","desktop-apps","package","qt"],"not_affected_if":["no-untrusted-binary-json"],"how_to_check":"- unknown","fix":"- unknown","status":"open","published_at":"2026-10-20T09:17:08+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","triaged_at":"2026-10-25T04:39:26+00:00","updated_at":"2026-10-25T04:39:26+00:00","category":"package","confidence":0.5,"triage":{"at":"2026-10-25T04:39:26Z","model":"claude-haiku-5-5","output":{"fix":"- unknown","reach":"unknown","title":"Qt: malformed binary JSON header causes out-of-bounds read","impact":"low","summary":"A malformed header in binary data passed to QBinaryJson::fromBinaryData() in Qt triggers an out-of-bounds read, which is undefined behaviour. The sources do not say whether this leads to code execution or only a crash or information leak.","category":"package","nicknames":[],"who_cares":["qt","c++","desktop-apps"],"confidence":0.5,"needs_auth":"unknown","worst_case":"out-of-bounds memory read; impact beyond a crash unknown","analyst_note":"Check the NVD entry and the Qt advisory for affected versions, the fixed release, and whether the flaw is reachable from untrusted input.","how_to_check":"- unknown","needs_analyst":true,"not_affected_if":["no-untrusted-binary-json"],"who_is_affected":"Applications built on Qt's JSON binary format code path that parse untrusted binary JSON data through QBinaryJson::fromBinaryData() are the ones to look at. Applications that only handle their own trusted JSON or never parse binary JSON input can likely skip it. The sources do not list affected Qt versions.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.000561,"input_tokens":3272,"output_tokens":467,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-101201':14A,17A '-2026':13A,16A 'app':21B 'behaviour':46B,79C 'binari':3A,28B,70C 'bound':10A,41B,85C 'c':18B 'caus':6A,77C 'code':56B 'crash':61B 'cve':12A,15A 'data':29B 'desktop':20B 'desktop-app':19B 'execut':57B 'fed':72C 'file':71C 'frombinarydata':33B,75C 'header':5A,26B,67C 'inform':63B 'json':4A 'lead':54B 'leak':64B 'malform':2A,25B,66C 'out-of-bound':7A,38B,82C 'packag':22B 'pass':30B 'qbinaryjson':32B,74C 'qt':1A,23B,35B 'read':11A,42B,86C 'say':51B 'sourc':48B 'trigger':36B 'undefin':45B,78C 'whether':52B","nicknames":[],"mitigations":[],"who_affected":"Applications built on Qt's JSON binary format code path that parse untrusted binary JSON data through QBinaryJson::fromBinaryData() are the ones to look at. Applications that only handle their own trusted JSON or never parse binary JSON input can likely skip it. The sources do not list affected Qt versions.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T09:17:08+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:U/V:X/RE:L/U:Amber","cvss_by":"a59d8014-47c4-4630-ab43-e1b13cbe58e3","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-101201","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101201","severity":null,"published_at":"2026-10-20T09:17:08+00:00","modified_at":"2026-10-20T19:59:00+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","fetched_at":"2026-10-23T22:28:57+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}