{"id":"CVE-2026-121965","kind":"vulnerability","aliases":["CVE-2026-121965"],"related":[],"title":"Parse Server: prototype pollution lets a client break built-in functions","description":"Parse Server before 8.6.113 and 9.0.0 before 9.10.6-alpha.5 contains a prototype pollution vulnerability when building objects for Cloud Code triggers and LiveQuery, where a dot notation key whose intermediate segment resolves through an inherited member writes onto a process-wide built-in. Clients with write access to an object in a class with a trigger or LiveQuery can corrupt a built-in function, making unrelated requests fail until restart and denying service to all clients and hosted applications.","summary":"Parse Server builds objects for Cloud Code triggers and LiveQuery in a way that lets a dot-notation key write onto a process-wide built-in. A client with write access to an object in a class with a trigger or LiveQuery can corrupt that built-in, causing unrelated requests to fail until restart.","severity":"medium","cvss":6.0,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["backend-as-a-service","node.js","package","parse-server","self-hosted"],"not_affected_if":["livequery-disabled","no-cloud-code-triggers"],"how_to_check":"- Check the installed Parse Server version with `npm ls parse-server` or the `version` field in its package.json.\n- Look for Cloud Code triggers or LiveQuery enabled on any class your clients can write to.","fix":"- Parse Server 8.x: move to `8.6.113` or later.\n- Parse Server 9.x: move to `9.10.6-alpha.5` or later (9.0.0 is affected).","status":"open","published_at":"2026-11-04T16:17:49+00:00","first_seen_at":"2026-11-04T16:28:15+00:00","triaged_at":"2026-11-04T16:28:59+00:00","updated_at":"2026-11-04T16:28:59+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-04T16:28:59Z","model":"claude-haiku-5-5","output":{"fix":"- Parse Server 8.x: move to `8.6.113` or later.\n- Parse Server 9.x: move to `9.10.6-alpha.5` or later (9.0.0 is affected).","reach":"network","title":"Parse Server: prototype pollution lets a client break built-in functions","impact":"medium","summary":"Parse Server builds objects for Cloud Code triggers and LiveQuery in a way that lets a dot-notation key write onto a process-wide built-in. A client with write access to an object in a class with a trigger or LiveQuery can corrupt that built-in, causing unrelated requests to fail until restart.","audience":"developers","category":"package","nicknames":[],"who_cares":["parse-server","node.js","self-hosted","backend-as-a-service"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Denial of service across the server and every hosted application","analyst_note":"Confirm the exact trigger and LiveQuery conditions and whether a default configuration is exposed, via the vendor advisory on github.com and the VulnCheck advisory.","how_to_check":"- Check the installed Parse Server version with `npm ls parse-server` or the `version` field in its package.json.\n- Look for Cloud Code triggers or LiveQuery enabled on any class your clients can write to.","plain_action":"","needs_analyst":true,"not_affected_if":["no-cloud-code-triggers","livequery-disabled"],"who_is_affected":"Teams running Parse Server with Cloud Code triggers or LiveQuery on classes that clients can write to are exposed. Deployments without triggers or LiveQuery on writable classes can likely skip it, though the sources do not state this explicitly.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.00074,"input_tokens":4248,"output_tokens":630,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-121965':15A,18A '-2026':14A,17A '8.6.113':93C '9.0.0':95C '9.10.6':97C 'access':65B,138C 'alpha.5':98C 'applic':171C 'backend':20B 'backend-as-a-servic':19B 'break':8A 'build':34B,105C 'built':10A,59B,81B,133C,154C 'built-in':9A,58B,80B,132C,153C 'caus':83B 'class':71B,144C 'client':7A,62B,135C,168C 'cloud':37B,108C 'code':38B,109C 'contain':99C 'corrupt':78B,151C 'cve':13A,16A 'deni':164C 'dot':49B,115C 'dot-not':48B 'fail':87B,160C 'function':12A,156C 'host':31B,170C 'inherit':124C 'intermedi':119C 'key':51B,117C 'let':5A,46B 'livequeri':41B,76B,112C,149C 'make':157C 'member':125C 'node.js':24B 'notat':50B,116C 'object':35B,68B,106C,141C 'onto':53B,127C 'packag':25B 'pars':1A,27B,32B,90C 'parse-serv':26B 'pollut':4A,102C 'process':56B,130C 'process-wid':55B,129C 'prototyp':3A,101C 'request':85B,159C 'resolv':121C 'restart':89B,162C 'segment':120C 'self':30B 'self-host':29B 'server':2A,28B,33B,91C 'servic':23B,165C 'trigger':39B,74B,110C,147C 'unrel':84B,158C 'vulner':103C 'way':44B 'whose':118C 'wide':57B,131C 'write':52B,64B,126C,137C","nicknames":[],"mitigations":[],"who_affected":"Teams running Parse Server with Cloud Code triggers or LiveQuery on classes that clients can write to are exposed. Deployments without triggers or LiveQuery on writable classes can likely skip it, though the sources do not state this explicitly.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["backendasaservice","medium","nodejs","package","parseserver","selfhosted"],"campaign_type":null,"first_public_at":"2026-10-20T18:20:00+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-2026-121965","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121965","severity":null,"published_at":"2026-11-04T16:17:49+00:00","modified_at":"2026-11-04T16:17:50+00:00","first_seen_at":"2026-11-04T16:28:15+00:00","fetched_at":"2026-11-04T16:28:15+00:00","note":null}],"documents":[{"id":68503,"url":"https://github.com/parse-community/parse-server/security/advisories/GHSA-95hp-82c6-25q5","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-20T18:20:00+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":68504,"url":"https://www.vulncheck.com/advisories/parse-server-before-8.6.113-and-9.10.6-alpha.5-prototype-pollution-via-dot-notation-key","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}