CVE-2026-85738

TREK is a collaborative travel planner. Prior to 3.4.0, the checkSsrf logic in server/src/utils/ssrfGuard.ts does not recognize NAT64, 6to4, or Teredo IPv6 transition addresses that encode an IPv4 destination. An authenticated user who controls a DNS record can supply a URL whose AAAA result is a transition address embedding a private, loopback, or link-local IPv4 target, and isAlwaysBlocked and isPrivateNetwork classify the address as allowed. In a deployment that routes the applicable transition format, user-facing imports, webhooks, integrations, or plugin egress can reach internal services or cloud metadata and expose returned information. This issue is fixed in version 3.4.0.

• https://github.com/liketrek/TREK/commit/a2bd9be184a94997105ce190dad920c41e7b10df
• https://github.com/liketrek/TREK/pull/1540
• https://github.com/liketrek/TREK/releases/tag/v3.4.0
• https://github.com/liketrek/TREK/security/advisories/GHSA-9hpq-mrpx-mcxg
• https://github.com/liketrek/TREK/security/advisories/GHSA-9hpq-mrpx-mcxg