{"id":"CVE-2026-55883","aliases":["GHSA-6m68-r693-78qx","GO-2026-5181"],"url":"https://o3.security/vulnerability/CVE-2026-55883","summary":"Tilt: Cross-site WebSocket hijacking of the Tilt HUD stream","details":"## Summary\nThe Tilt HUD WebSocket (`/ws/view`) is gated by a CSRF token, but the token is served by an unauthenticated endpoint and the upgrader accepts any client that omits an `Origin` header. When the HUD is network-exposed, an attacker can open the HUD stream and read the developer's session state.\n\n## Details\nThe upgrader accepts a connection when the `csrf` query parameter matches a process-wide token (`websocketCSRFToken`). That token is served as `text/plain` by an unauthenticated handler (`WebsocketToken`, mounted at `/api/websocket_token`), so any reachable caller can fetch it and connect to `/ws/view?csrf=<token>`. When the parameter does not match, the upgrader falls back to a same-origin check that returns true when the `Origin` header is absent, so a non-browser client that omits `Origin` is accepted anyway. The token has no per-session binding.\n\n## Impact\nAn attacker who can reach the HUD listener can open the HUD WebSocket and receive the full view stream — session state, Tiltfile contents, resource statuses, and continued updates — defeating the intended anti-CSWSH protection.\n\n### Conditions for exploitation\n- Affected version in `>= 0.24.0, <= 0.37.3`.\n- HUD bound to a non-loopback address (`tilt up --host 0.0.0.0`, or `TILT_HOST` set).\n- Network reachability to the listener (default port `10350`).\n\n### Not affected\n- The default loopback-only bind is not reachable from the network.\n\n## Workarounds\nUse the default loopback bind (omit `--host`, unset `TILT_HOST`). No complete workaround short of upgrading for non-loopback deployments.","published":"2026-07-10T21:38:18.081Z","modified":"2026-08-12T03:51:19.713487148Z","cvss":null,"epss":{"score":0.00262,"percentile":0.1821,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/tilt-dev/tilt","fixedVersion":"0.37.4"}],"fix":{"url":"https://github.com/tilt-dev/tilt/commit/47393fba7f6ef5e305d5e814551feef8e4acbc0a","label":"tilt-dev/tilt@47393fb"},"references":[{"type":"WEB","url":"https://github.com/tilt-dev/tilt/releases/tag/v0.37.4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55883.json"},{"type":"ADVISORY","url":"https://github.com/tilt-dev/tilt/security/advisories/GHSA-6m68-r693-78qx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55883"},{"type":"FIX","url":"https://github.com/tilt-dev/tilt/commit/47393fba7f6ef5e305d5e814551feef8e4acbc0a"},{"type":"FIX","url":"https://github.com/tilt-dev/tilt/pull/6776"},{"type":"PACKAGE","url":"https://github.com/tilt-dev/tilt"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:19.713487148Z"}}