high8.7
CVE-2026-55245
Bifrost's SSRF deny-list is incomplete: isPublicIP permits CGNAT, IPv6 6to4/NAT64, and site-local in FetchAndEncodeURL
Impact
Bifrost is an enterprise AI gateway for routing requests to model providers. Prior to 1.5.17, the isPublicIP function in core/providers/utils/fetch.go, reached through FetchAndEncodeURL for Bedrock and Vertex image or document URLs, classifies Carrier-Grade NAT 100.64.0.0/10, IPv6 6to4 2002::/16, NAT64 64:ff9b::/96 and 64:ff9b:1::/48, and deprecated IPv6 site-local fec0::/10 addresses as public. A remote attacker who controls a multimodal request URL can make the gateway fetch internal services, including a cloud instance metadata endpoint encoded through 6to4 or NAT64. This issue is fixed in version 1.5.17.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/maximhq/bifrost/core | < 1.5.17 | 1.5.17 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-w98g-5w9p-p3rc
- https://github.com/maximhq/bifrost/security/advisories/GHSA-w98g-5w9p-p3rc
- https://github.com/maximhq/bifrost/pull/4092
- https://github.com/maximhq/bifrost/commit/54ec431fc5255ff42c36420d88549477e0b33d89
- https://github.com/maximhq/bifrost/releases/tag/core/v1.5.17