CVE-2026-55245
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.
What this means for your business
- FIRST's prediction model gives it a 0.4% chance of attack attempts being seen in the next 30 days, ranking above 37% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- Not yet scored
- CVSS v4
- 8.7
- Weakness
- CWE-918
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-08-28
- Last modified
- 2026-09-09
- Sources
- NVD
References
- https://github.com/maximhq/bifrost/commit/54ec431fc5255ff42c36420d88549477e0b33d89
- https://github.com/maximhq/bifrost/pull/4092
- https://github.com/maximhq/bifrost/releases/tag/core/v1.5.17
- https://github.com/maximhq/bifrost/security/advisories/GHSA-w98g-5w9p-p3rc
- https://github.com/maximhq/bifrost/security/advisories/GHSA-w98g-5w9p-p3rc