What’s Vulnerable › Vulnerabilities

CVE-2026-85738: TREK: SSRF Guard Bypass via IPv6 Transition Addresses (NAT64/6to4)

• Severity: medium (CVSS 6.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-24 · updated 2026-09-28
• Weakness: CWE-918

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.

Affected products

• liketrek TREK: before 3.4.0

References

• 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

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