{"id":"CVE-2026-109823","kind":"vulnerability","aliases":["CVE-2026-109823"],"related":[],"title":"Tidewave: local dev server leaks project filesystem paths via DNS rebinding","description":"An attacker can read the name of filesystem paths of your application present via Tidewave configuration via /tidewave/connect or via the rendered toolbar.\n\nNeither response checks the Host header. A web page that rebinds its own domain to the loopback address can therefore read the tag with a same-origin request, which carries no Origin header. The paths usually reveal the local username and the project layout.\n\nThis issue affects tidewave: from 0.8.0 before 0.9.2.","summary":"Tidewave, a development tool, exposes the names of filesystem paths in its configuration endpoint and rendered toolbar without checking the Host header. A web page that rebinds its domain to the loopback address can read those paths, which usually reveal the local username and project layout.","severity":"low","cvss":2.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["elixir","local-development","package","ruby","tidewave"],"not_affected_if":["already-on-0.9.2-or-later","not-running-tidewave"],"how_to_check":"- Check the installed tidewave version, for example `mix deps` or the lockfile entry, and confirm whether it is `0.8.0` or later but before `0.9.2`.\n- Confirm whether the Tidewave dev server runs while a browser is open on the same machine.","fix":"- Upgrade tidewave to `0.9.2` or later.","status":"open","published_at":"2026-10-27T16:17:29+00:00","first_seen_at":"2026-10-27T16:33:07+00:00","triaged_at":"2026-10-27T16:34:28+00:00","updated_at":"2026-10-27T16:34:28+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-10-27T16:34:28Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade tidewave to `0.9.2` or later.","reach":"local","title":"Tidewave: local dev server leaks project filesystem paths via DNS rebinding","impact":"low","summary":"Tidewave, a development tool, exposes the names of filesystem paths in its configuration endpoint and rendered toolbar without checking the Host header. A web page that rebinds its domain to the loopback address can read those paths, which usually reveal the local username and project layout.","category":"package","nicknames":[],"who_cares":["tidewave","local-development","ruby","elixir"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker reads local filesystem path names, revealing username and project layout.","analyst_note":"","how_to_check":"- Check the installed tidewave version, for example `mix deps` or the lockfile entry, and confirm whether it is `0.8.0` or later but before `0.9.2`.\n- Confirm whether the Tidewave dev server runs while a browser is open on the same machine.","needs_analyst":false,"not_affected_if":["already-on-0.9.2-or-later","not-running-tidewave"],"who_is_affected":"Developers running the Tidewave development server on a machine with a version from 0.8.0 before 0.9.2. The sources describe a local loopback exposure through DNS rebinding, so the risk is limited to a developer's own workstation and not to deployed production systems. Teams that do not run Tidewave in development, or that already run 0.9.2 or later, can skip it.","user_interaction":"yes","needs_special_setup":"unknown","severity_if_unknown":"low"},"cost_usd":0.000615,"input_tokens":3356,"output_tokens":558,"severity_before":"low"},"analyst_status":null,"analyst_note":null,"search":"'-109823':14A,17A '-2026':13A,16A '/tidewave/connect':88C '0.8.0':144C '0.9.2':146C 'address':57B,111C 'affect':141C 'applic':82C 'attack':72C 'carri':124C 'check':43B,96C 'configur':37B,86C 'cve':12A,15A 'dev':3A 'develop':21B,27B 'dns':10A 'domain':53B,107C 'elixir':18B 'endpoint':38B 'expos':29B 'filesystem':7A,33B,78C 'header':46B,99C,127C 'host':45B,98C 'issu':140C 'layout':70B,138C 'leak':5A 'local':2A,20B,66B,133C 'local-develop':19B 'loopback':56B,110C 'name':31B,76C 'neither':94C 'origin':121C,126C 'packag':22B 'page':49B,102C 'path':8A,34B,61B,79C,129C 'present':83C 'project':6A,69B,137C 'read':59B,74C,114C 'rebind':11A,51B,104C 'render':40B,92C 'request':122C 'respons':95C 'reveal':64B,131C 'rubi':23B 'same-origin':119C 'server':4A 'tag':116C 'therefor':113C 'tidewav':1A,24B,25B,85C,142C 'tool':28B 'toolbar':41B,93C 'usernam':67B,134C 'usual':63B,130C 'via':9A,84C,87C,90C 'web':48B,101C 'without':42B","nicknames":[],"mitigations":[],"who_affected":"Developers running the Tidewave development server on a machine with a version from 0.8.0 before 0.9.2. The sources describe a local loopback exposure through DNS rebinding, so the risk is limited to a developer's own workstation and not to deployed production systems. Teams that do not run Tidewave in development, or that already run 0.9.2 or later, can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T16:17:29+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/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":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-109823","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-109823","severity":null,"published_at":"2026-10-27T16:17:29+00:00","modified_at":"2026-10-27T16:17:29+00:00","first_seen_at":"2026-10-27T16:33:07+00:00","fetched_at":"2026-10-27T16:33:07+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"}