CVE-2026-63188: Logto-Io Logto

High severity, CVSS 8.7. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Logto-Io Logto: before 0.3.9 (fixed in 0.3.9)

Published 2026-08-19. Last modified 2026-09-09.