{"id":"CVE-2026-119978","kind":"vulnerability","aliases":["CVE-2026-119978"],"related":[],"title":"Flowise: authenticated users can run OS commands through custom functions","description":"Flowise through 3.1.4 contains a sandbox escape vulnerability that allows authenticated users to execute OS commands by abusing allowlisted langchain and mammoth modules when ALLOW_BUILTIN_DEP=true. Attackers can submit JavaScript to /api/v1/node-custom-function that writes a file into the mammoth package via LocalFileStore and requires it, escaping vm2 as the Flowise process user.","summary":"Self-hosted Flowise up to 3.1.4 is exposed when ALLOW_BUILTIN_DEP=true and someone with a login or API key can reach /api/v1/node-custom-function. They can write a file into the mammoth package via the langchain LocalFileStore, require it, escape vm2 and run OS commands as the Flowise user (root in the official Docker image). Instances without ALLOW_BUILTIN_DEP=true or without untrusted users can skip it. No fixed version is published yet.","severity":"critical","cvss":9.0,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"flowise","fixed":[],"affected":"<= 3.1.4","ecosystem":"npm"}],"ecosystems":[],"tags":["ai-tooling","flowise","langchain","node","self-hosted"],"not_affected_if":["auth-required","default-config","no-untrusted-accounts"],"how_to_check":"- Check the installed Flowise version against the affected range through 3.1.4.\n- Check whether `ALLOW_BUILTIN_DEP` is set to `true` in the Flowise environment.\n- Check whether the `/api/v1/node-custom-function` endpoint is reachable by untrusted users.","fix":null,"status":"open","published_at":"2026-10-30T18:17:27+00:00","first_seen_at":"2026-10-30T18:55:29+00:00","triaged_at":"2026-10-30T18:56:31+00:00","updated_at":"2026-10-30T18:57:43+00:00","category":"ai-tooling","confidence":0.6,"triage":{"at":"2026-10-30T18:56:31Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Flowise: authenticated users can run OS commands through custom functions","impact":"high","summary":"Flowise through version 3.1.4 has a sandbox escape that lets a logged-in user submit JavaScript to the custom function endpoint and break out of the vm2 sandbox. The attacker then runs operating system commands as the Flowise process user.","audience":"businesses","category":"ai-tooling","nicknames":[],"who_cares":["flowise","self-hosted","langchain","node"],"confidence":0.7,"fix_status":"unknown","needs_auth":"yes","worst_case":"Attacker runs OS commands as the Flowise process user","analyst_note":"Find the fixed Flowise version and any vendor advisory; the NVD entry in the sources does not state a fix.","how_to_check":"- Check the installed Flowise version against the affected range through 3.1.4.\n- Check whether `ALLOW_BUILTIN_DEP` is set to `true` in the Flowise environment.\n- Check whether the `/api/v1/node-custom-function` endpoint is reachable by untrusted users.","plain_action":"","needs_analyst":true,"not_affected_if":["default-config","no-untrusted-accounts"],"who_is_affected":"Teams running self-hosted Flowise through 3.1.4 where users have accounts. The description says exploitation depends on `ALLOW_BUILTIN_DEP=true`, so default-configured installs may be less exposed. unknown whether a fixed version exists.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"critical"},"cost_usd":0.0007,"input_tokens":4176,"output_tokens":564,"severity_before":"critical"},"analyst_status":"done","analyst_note":"Find the fixed Flowise version and any vendor advisory; the NVD entry in the sources does not state a fix.","search":"'-119978':13A,16A '-2026':12A,15A '/api/v1/node-custom-function':51B,135C '3.1.4':33B,104C 'abus':119C 'ai':19B 'ai-tool':18B 'allow':37B,85B,111C,126C 'allowlist':120C 'api':47B 'attack':130C 'authent':2A,112C 'builtin':38B,86B,127C 'command':7A,72B,117C 'contain':105C 'custom':9A 'cve':11A,14A 'dep':39B,87B,128C 'docker':81B 'escap':67B,108C,149C 'execut':115C 'expos':35B 'file':56B,139C 'fix':97B 'flowis':1A,21B,30B,75B,102C,153C 'flowise':17A 'function':10A 'host':26B,29B 'imag':82B 'instanc':83B 'javascript':133C 'key':48B 'langchain':22B,63B,121C 'localfilestor':64B,145C 'login':45B 'mammoth':59B,123C,142C 'modul':124C 'node':23B 'offici':80B 'os':6A,71B,116C 'packag':60B,143C 'process':154C 'publish':100B 'reach':50B 'requir':65B,147C 'root':77B 'run':5A,70B 'sandbox':107C 'self':25B,28B 'self-host':24B,27B 'skip':94B 'someon':42B 'submit':132C 'tool':20B 'true':40B,88B,129C 'untrust':91B 'user':3A,76B,92B,113C,155C 'version':98B 'via':61B,144C 'vm2':68B,150C 'vulner':109C 'without':84B,90B 'write':54B,137C 'yet':101B","nicknames":[],"mitigations":[],"who_affected":"Teams running self-hosted Flowise through 3.1.4 where users have accounts. The description says exploitation depends on `ALLOW_BUILTIN_DEP=true`, so default-configured installs may be less exposed. unknown whether a fixed version exists.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T18:17:27+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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-2026-119978","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-119978","severity":null,"published_at":"2026-10-30T18:17:27+00:00","modified_at":"2026-10-30T18:17:27+00:00","first_seen_at":"2026-10-30T18:55:29+00:00","fetched_at":"2026-10-30T18:55:29+00:00","note":null},{"source":"analyst","external_id":"CVE-2026-119978:1181","url":null,"severity":null,"published_at":"2026-10-30T18:57:43+00:00","modified_at":"2026-10-30T18:57:43+00:00","first_seen_at":"2026-10-30T18:57:43+00:00","fetched_at":"2026-10-30T18:57:43+00:00","note":"No Flowise advisory or fix found for this CVE; NVD/OpenCVE say affected <=3.1.4 and 3.1.4 is the latest release (Vulert, 28 Oct), so no known fixed version. Sibling GHSA-9gvv-qjj3-2p6g (puppeteer allowlist, same endpoint, fixed 3.1.3) is a different path (this one: langchain LocalFileStore + mammoth). Nothing verified. Recheck Flowise advisories/releases after 3.1.4."}],"documents":[{"id":25336,"url":"https://app.opencve.io/cve/CVE-2026-119978","title":"OpenCVE: CVE-2026-119978 (mirrors NVD description)","kind":"other","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"describes","confidence":null,"note":null},{"id":25337,"url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-9gvv-qjj3-2p6g","title":"Flowise GHSA-9gvv-qjj3-2p6g: sibling sandbox escape via puppeteer allowlist, fixed 3.1.3","kind":"advisory","source":"analyst","publisher":null,"text":null,"published_at":null,"relation":"mentions","confidence":null,"note":null}],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}