CVE-2026-55245: maximhq bifrost Server-Side Request Forgery (SSRF)

Vulnerability summary

CVE-2026-55245 is a high (CVSS 8.7) Server-Side Request Forgery (SSRF) vulnerability in maximhq bifrost. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.5% of scored vulnerabilities.

Timeline

1. 28-08-2026
   PublishedVulnerability first disclosed.
2. 28-08-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-918Server-Side Request Forgery (SSRF)The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.