{"id":"CVE-2026-119569","kind":"vulnerability","aliases":["CVE-2026-119569"],"related":[],"title":"Parse Server: prototype pollution from user keys breaks requests until restart","description":"Parse Server before 8.6.108 and 9.0.0 before 9.10.5-alpha.9 contains a prototype pollution vulnerability because user-controlled keys are expanded into objects without own-property checks. Clients with class write access can send dot notation field keys or ACL entry names matching built-in object members to corrupt built-in functions, causing all requests to fail until server restart.","summary":"Parse Server expands user-supplied field keys and ACL entry names into objects without own-property checks, so crafted keys can overwrite built-in object members. A client with class write access can corrupt built-in functions, causing all requests to fail until the server restarts.","severity":"medium","cvss":6.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["backend","node","package","parse-server","self-hosted"],"not_affected_if":["already-patched","no-untrusted-class-write"],"how_to_check":"- Check the installed Parse Server version with `npm ls parse-server` or the version in `package.json`.\n- Confirm whether any client has class write access, since the sources say that is required.","fix":"- Move Parse Server 8.x to `8.6.108` or later.\n- Move Parse Server 9.x to `9.10.5-alpha.9` or later.","status":"open","published_at":"2026-10-30T14:16:45+00:00","first_seen_at":"2026-10-30T14:30:53+00:00","triaged_at":"2026-10-30T14:32:54+00:00","updated_at":"2026-10-30T14:32:54+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-30T14:32:54Z","model":"claude-haiku-5-5","output":{"fix":"- Move Parse Server 8.x to `8.6.108` or later.\n- Move Parse Server 9.x to `9.10.5-alpha.9` or later.","reach":"network","title":"Parse Server: prototype pollution from user keys breaks requests until restart","impact":"medium","summary":"Parse Server expands user-supplied field keys and ACL entry names into objects without own-property checks, so crafted keys can overwrite built-in object members. A client with class write access can corrupt built-in functions, causing all requests to fail until the server restarts.","audience":"developers","category":"package","nicknames":[],"who_cares":["parse-server","node","self-hosted","backend"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Denial of service until the server restarts; built-in functions corrupted","analyst_note":"","how_to_check":"- Check the installed Parse Server version with `npm ls parse-server` or the version in `package.json`.\n- Confirm whether any client has class write access, since the sources say that is required.","plain_action":"","needs_analyst":false,"not_affected_if":["already-patched","no-untrusted-class-write"],"who_is_affected":"Teams running Parse Server 8.x before 8.6.108 or 9.x before 9.10.5-alpha.9 are exposed. Exploitation needs a client with class write access, so apps where only trusted server code writes data are lower risk. Deployments that can skip it are those already on the fixed versions.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.00069,"input_tokens":4164,"output_tokens":548,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-119569':14A,17A '-2026':13A,16A '8.6.108':80C '9.0.0':82C '9.10.5':84C 'access':61B,109C 'acl':36B,117C 'alpha.9':85C 'backend':18B 'break':8A 'built':52B,65B,122C,129C 'built-in':51B,64B,121C,128C 'caus':68B,132C 'check':45B,104C 'class':59B,107C 'client':57B,105C 'contain':86C 'control':94C 'corrupt':63B,127C 'craft':47B 'cve':12A,15A 'dot':112C 'entri':37B,118C 'expand':29B,97C 'fail':72B,136C 'field':33B,114C 'function':67B,131C 'host':26B 'key':7A,34B,48B,95C,115C 'match':120C 'member':55B,125C 'name':38B,119C 'node':19B 'notat':113C 'object':40B,54B,99C,124C 'overwrit':50B 'own-properti':42B,101C 'packag':20B 'pars':1A,22B,27B,77C 'parse-serv':21B 'pollut':4A,89C 'properti':44B,103C 'prototyp':3A,88C 'request':9A,70B,134C 'restart':11A,76B,139C 'self':25B 'self-host':24B 'send':111C 'server':2A,23B,28B,75B,78C,138C 'suppli':32B 'user':6A,31B,93C 'user-control':92C 'user-suppli':30B 'vulner':90C 'without':41B,100C 'write':60B,108C","nicknames":[],"mitigations":[],"who_affected":"Teams running Parse Server 8.x before 8.6.108 or 9.x before 9.10.5-alpha.9 are exposed. Exploitation needs a client with class write access, so apps where only trusted server code writes data are lower risk. Deployments that can skip it are those already on the fixed versions.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"first_public_at":"2026-10-30T14:16:45+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-119569","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119569","severity":null,"published_at":"2026-10-30T14:16:45+00:00","modified_at":"2026-10-30T14:16:45+00:00","first_seen_at":"2026-10-30T14:30:53+00:00","fetched_at":"2026-10-30T14:30:53+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"}