{"id":"CVE-2026-116679","kind":"vulnerability","aliases":["CVE-2026-116679","GHSA-5cp7-fp4j-wwcv"],"related":[],"title":"Neko: Authorization bypass in legacy WebRTC input handling","description":"### Impact\n\nWhen legacy mode is enabled and `session.implicit_hosting` is enabled, the legacy WebRTC data channel incorrectly authorizes input events due to a logic error in `LegacyIsHost()`.\n\nAs a result, an authenticated room member may be able to send mouse and keyboard input through the legacy WebRTC control channel even when controls are locked or the member would otherwise not be authorized through the modern control API.\n\nThe issue affects only the legacy WebRTC input path. The modern HTTP/WebSocket control path correctly enforces authorization checks and is not affected.\n\nTo exploit this issue, an attacker must:\n\n* Be authenticated as a room member.\n* Successfully establish a WebRTC connection.\n* Access a deployment using the legacy WebRTC input handler.\n\nNo unauthenticated access or privilege escalation outside the application is possible.\n\n### Patches\n\nThe issue has been fixed in **[v3.1.5](https://github.com/m1k1o/neko/releases/tag/v3.1.5)** by correcting the authorization logic in the legacy WebRTC handler.\n\nUsers should upgrade to **[v3.1.5](https://github.com/m1k1o/neko/releases/tag/v3.1.5)** or later. Fix: *[395ca1a](https://github.com/m1k1o/neko/commit/395ca1a6f62b7b0e270e654d366a2d57b8042efd)*\n\n### Workarounds\n\nUsers who cannot immediately upgrade can mitigate the issue by one of the following:\n\n* Disable legacy mode if it is not required.\n* Disable implicit hosting (`session.implicit_hosting=false`).\n* Restrict access to trusted authenticated users.\n\n### Credits\n\nThanks to @KasperBuilds for responsibly disclosing this vulnerability and reaching out directly. This contribution helped strengthen the project, and the whole community benefits from it.","summary":"Neko is a self-hosted virtual browser that runs in Docker and streams over WebRTC. In versions 3.0.0 through 3.1.4, a host-check bug in legacy mode with implicit hosting lets an authenticated room member send mouse and keyboard input over the legacy data channel even when controls are locked.","severity":"medium","cvss":5.4,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"github.com/m1k1o/neko/server","fixed":["0.0.0-20260805142851-395ca1a6f62b"],"affected":">= 0.0.0-20250401220545-fe94c999c6af, < 0.0.0-20260805142851-395ca1a6f62b","ecosystem":"go"}],"ecosystems":["go"],"tags":["cwe-863","docker","neko","other","self-hosted","webrtc"],"not_affected_if":["auth-required","default-config"],"how_to_check":"- Check the Neko version in the running image tag, `3.1.4` or earlier means affected\n- Look for `legacy` mode and `session.implicit_hosting` enabled in the Neko configuration\n- unknown whether the sources list other specific checks","fix":"- Upgrade Neko to `3.1.5` or later\n- unknown whether a configuration-only workaround exists","status":"open","published_at":"2026-10-27T18:17:35+00:00","first_seen_at":"2026-10-27T18:32:59+00:00","triaged_at":"2026-10-27T18:34:55+00:00","updated_at":"2026-10-27T21:09:20+00:00","category":"other","confidence":0.6,"triage":{"at":"2026-10-27T18:34:55Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade Neko to `3.1.5` or later\n- unknown whether a configuration-only workaround exists","reach":"internet","title":"Neko virtual browser: legacy WebRTC input bypasses control locks in some setups","impact":"medium","summary":"Neko is a self-hosted virtual browser that runs in Docker and streams over WebRTC. In versions 3.0.0 through 3.1.4, a host-check bug in legacy mode with implicit hosting lets an authenticated room member send mouse and keyboard input over the legacy data channel even when controls are locked.","category":"other","nicknames":[],"who_cares":["neko","self-hosted","docker","webrtc"],"confidence":0.6,"needs_auth":"yes","worst_case":"Authenticated room member controls the browser despite locks","analyst_note":"","how_to_check":"- Check the Neko version in the running image tag, `3.1.4` or earlier means affected\n- Look for `legacy` mode and `session.implicit_hosting` enabled in the Neko configuration\n- unknown whether the sources list other specific checks","needs_analyst":false,"not_affected_if":["default-config","auth-required"],"who_is_affected":"Teams running self-hosted Neko from 3.0.0 through 3.1.4 with legacy mode and session.implicit_hosting enabled. The flaw needs an authenticated room member who can open a WebRTC connection, so deployments that run with the default modern control API or with implicit hosting off are not exposed.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000618,"input_tokens":3408,"output_tokens":554,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-116679':11A,19A '-2026':10A,18A '-863':24B '/m1k1o/neko/commit/395ca1a6f62b7b0e270e654d366a2d57b8042efd)*':246C '/m1k1o/neko/releases/tag/v3.1.5)**':221C,239C '/m1k1o/neko/server':22A '3.0.0':50B '3.1.4':52B '395ca1a':243C '5cp7':14A 'abl':120C 'access':191C,202C,277C 'affect':153C,172C 'api':150C 'applic':208C 'attack':178C 'authent':66B,115C,181C,280C 'author':2A,101C,145C,167C,225C 'benefit':305C 'browser':39B 'bug':57B 'bypass':3A 'cannot':250C 'channel':78B,99C,132C 'check':56B,168C 'communiti':304C 'connect':190C 'contribut':296C 'control':81B,131C,135C,149C,163C 'correct':165C,223C 'credit':282C 'cve':9A,17A 'cwe':23B 'data':77B,98C 'deploy':193C 'direct':294C 'disabl':262C,270C 'disclos':288C 'docker':25B,43B 'due':104C 'enabl':89C,94C 'enforc':166C 'error':108C 'escal':205C 'establish':187C 'even':79B,133C 'event':103C 'exploit':174C 'fals':275C 'fix':216C,242C 'follow':261C 'fp4j':15A 'ghsa':13A 'ghsa-5cp7-fp4j-wwcv':12A 'github.com':21A,220C,238C,245C 'github.com/m1k1o/neko/commit/395ca1a6f62b7b0e270e654d366a2d57b8042efd)*':244C 'github.com/m1k1o/neko/releases/tag/v3.1.5)**':219C,237C 'github.com/m1k1o/neko/server':20A 'handl':8A 'handler':199C,231C 'help':297C 'host':30B,37B,55B,63B,92C,272C,274C 'host-check':54B 'http/websocket':162C 'immedi':251C 'impact':84C 'implicit':62B,271C 'incorrect':100C 'input':7A,73B,102C,126C,158C,198C 'issu':152C,176C,213C,256C 'kasperbuild':285C 'keyboard':72B,125C 'later':241C 'legaci':5A,59B,76B,86C,96C,129C,156C,196C,229C,263C 'legacyishost':110C 'let':64B 'lock':83B,137C 'logic':107C,226C 'may':118C 'member':68B,117C,140C,185C 'mitig':254C 'mode':60B,87C,264C 'modern':148C,161C 'mous':70B,123C 'must':179C 'neko':1A,26B,32B 'one':258C 'otherwis':142C 'outsid':206C 'patch':211C 'path':159C,164C 'possibl':210C 'privileg':204C 'project':300C 'reach':292C 'requir':269C 'respons':287C 'restrict':276C 'result':113C 'room':67B,116C,184C 'run':41B 'self':29B,36B 'self-host':28B,35B 'send':69B,122C 'session.implicit':91C,273C 'stream':45B 'strengthen':298C 'success':186C 'thank':283C 'trust':279C 'unauthent':201C 'upgrad':234C,252C 'use':194C 'user':232C,248C,281C 'v3.1.5':218C,236C 'version':49B 'virtual':38B 'vulner':290C 'webrtc':6A,31B,47B,97C,130C,157C,189C,197C,230C 'whole':303C 'workaround':247C 'would':141C 'wwcv':16A","nicknames":[],"mitigations":[],"who_affected":"Teams running self-hosted Neko from 3.0.0 through 3.1.4 with legacy mode and session.implicit_hosting enabled. The flaw needs an authenticated room member who can open a WebRTC connection, so deployments that run with the default modern control API or with implicit hosting off are not exposed.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-27T18:17:35+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L","cvss_by":"GitHub","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-116679","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116679","severity":null,"published_at":"2026-10-27T18:17:35+00:00","modified_at":"2026-10-27T18:17:35+00:00","first_seen_at":"2026-10-27T18:32:59+00:00","fetched_at":"2026-10-27T18:32:59+00:00","note":null},{"source":"ghsa","external_id":"GHSA-5cp7-fp4j-wwcv","url":"https://github.com/advisories/GHSA-5cp7-fp4j-wwcv","severity":"medium","published_at":"2026-10-27T21:04:57+00:00","modified_at":"2026-10-27T21:04:58+00:00","first_seen_at":"2026-10-27T21:09:20+00:00","fetched_at":"2026-10-27T21:09:20+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"}