CVE-2026-103980: ideon: SSRF protection bypass via IPv6 transition addresses (NAT64 / 6to4 / IPv4-mapped) in link preview
ideon is a self-hosted visual workspace. Prior to version 0.9.6, the SSRF protection in safeFetch is bypassed by IPv6 transition addresses that embed private IPv4 addresses. The isPrivateIP function in src/app/lib/ssrf.ts checks only a narrow set of IPv6 ranges (loopback ::1, ULA fc/fd, link-local fe80) but does not recognize IPv4-mapped (::ffff:), NAT64 well-known (64:ff9b::/96, RFC 6052), NAT64 local-use (64:ff9b:1::/48, RFC 8215), 6to4 (2002::/16, RFC 3056), or Teredo (2001::/32, RFC 4380) encodings. An authenticated user can supply these addresses in link URLs to reach cloud metadata endpoints (169.254.169.254), localhost services, and RFC 1918 internal networks through the link preview metadata fetcher. This issue has been patched in version 0.9.6.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ideonto a version that resolves this vulnerability.Fixed in 0.9.6
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated ideon user can exploit it by submitting a link URL that uses an IPv6 transition address encoding a private or local IPv4 address. No user interaction is required beyond the application fetching link-preview metadata.
Which internal targets may be reachable through the bypass?
The link preview metadata fetcher may be used to reach cloud metadata endpoints such as 169.254.169.254, localhost services, and RFC 1918 internal networks. The bypass applies to IPv4-mapped, NAT64 well-known and local-use, 6to4, and Teredo IPv6 address forms.
Are installations affected by default?
The affected functionality is the safeFetch SSRF protection used by the link preview metadata fetcher. Installations running a version before 0.9.6 are affected when authenticated users can submit link URLs that trigger this fetcher.
What is the remediation?
Upgrade ideon to version 0.9.6, which patches the issue. The provided data does not specify an alternative mitigation for environments where upgrading is not immediately possible.