fkie_cve-2026-63188

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 0.3.9, the Logto Tunnel npm package enabled createStaticFileProxy from packages/tunnel/src/commands/tunnel/index.ts and passed request.url from static asset requests through packages/tunnel/src/commands/tunnel/utils.ts using path.join(staticPath, request.url) and then fs.open(requestPath, "r") without URL normalization or a containment check. When --experience-path was enabled and the tunnel port was reachable, an unauthenticated requester could send a path containing ../ to createStaticFileProxy and read files outside the configured static directory that were readable by the logto-tunnel process. The service used server.listen(port), which could expose the tunnel to other hosts depending on the platform and deployment. This issue is fixed in version 0.3.9.

GHSA-rxjr-6c9q-h67x — logto-tunnel serves files outside --experience-path via path traversal

Affected: npm: @logto/tunnel

### Summary

`@logto/tunnel` serves custom sign-in experience files from the `--experience-path` directory. When the tunnel service is reachable, a requester can use `../` path segments in a static asset request to read files outside that directory that the CLI process can read.

### Details

The tunnel command accepts `--experience-path` as the local folder path for custom sign-in experience assets. `packages/tunnel/src/commands/tunnel/index.ts` enables `createStaticFileProxy(path)` when that option is set and sends non-Logto, non-`--experience-uri` requests to that static proxy. The server is started with `server.listen(port)`.

`packages/tunnel/src/commands/tunnel/utils.ts` builds the filesystem path as `path.join(staticPath, fallBackToIndex ? index : request.url)`. For file asset paths, `request.url` is used directly. A request URL such as `/../secret.txt` resolves outside `staticPath` and is then opened with `fs.open(requestPath, 'r')`. There is no URL normalization and no containment check that the resolved path remains under the configured static directory before the file is read and returned.

The proof boundary is the packaged CLI end-to-end run. The filesystem read primitive was validated with equivalent Node HTTP handling for the affected code path, including that Node preserves `/../secret.txt` in `request.url` and that bare `server.listen(port)` binds to all interfaces on this platform.

### PoC

1. Create a custom UI directory at `/tmp/logto-ui/static` with `/t…

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fkie_cve-2026-63188

GHSA-rxjr-6c9q-h67x — logto-tunnel serves files outside --experience-path via path traversal