CVE-2026-55245
Bifrost: SSRF deny-list incomplete: isPublicIP permits CGNAT, IPv6 6to4/NAT64, and site-local in FetchAndEncodeURL
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.
INFO
Published Date :
Aug. 28, 2026, 8:18 p.m.
Last Modified :
Aug. 28, 2026, 10:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-55245
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Bifrost to version 1.5.17.
- Apply security patches to the Bifrost gateway.
- Validate network configurations post-update.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-55245.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55245 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-55245
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-55245 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55245 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 28, 2026
Action Type Old Value New Value Added Reference https://github.com/maximhq/bifrost/security/advisories/GHSA-w98g-5w9p-p3rc Added SSVC {'id': 'CVE-2026-55245', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-28T19:54:05.268770Z'} -
New CVE Received by [email protected]
Aug. 28, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-918 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/55xxx/CVE-2026-55245.json">CVE-2026-55245</a> Added Reference https://github.com/maximhq/bifrost/commit/54ec431fc5255ff42c36420d88549477e0b33d89 Added Reference https://github.com/maximhq/bifrost/pull/4092 Added Reference https://github.com/maximhq/bifrost/releases/tag/core/v1.5.17 Added Reference https://github.com/maximhq/bifrost/security/advisories/GHSA-w98g-5w9p-p3rc