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.
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History

Thu, 24 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Description 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.
Title TREK: SSRF Guard Bypass via IPv6 Transition Addresses (NAT64/6to4)
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-24T18:09:31.268Z

Reserved: 2026-09-04T14:50:16.719Z

Link: CVE-2026-85738

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-24T19:17:18.193

Modified: 2026-09-24T19:17:18.193

Link: CVE-2026-85738

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses