Claude Code is an agentic coding tool. From 0.2.54 until 2.1.163, because the hostname huggingface.co was pre-approved as a bare hostname for the WebFetch tool, any path on that domain—including attacker-controlled model repositories—was auto-approved without a permission prompt or being subject to --allowedTools restrictions. An attacker able to inject untrusted content into a Claude Code context could direct it to issue WebFetch requests against attacker-controlled repository files (e.g. /resolve/main/config.json), which HuggingFace counts as downloads server-side, creating a covert out-of-band channel for encoding and exfiltrating data Claude can access such as files, environment variables, or command output. Reliably exploiting this required the ability to add untrusted content into a Claude Code context window. This vulnerability is fixed in 2.1.163.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-fg94-h982-f3mm | Claude Code: Out-of-Band Data Exfiltration via Pre-Approved HuggingFace Domain in WebFetch |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 23 Jun 2026 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Anthropics
Anthropics claude Code |
|
| Vendors & Products |
Anthropics
Anthropics claude Code |
Tue, 23 Jun 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 23 Jun 2026 17:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Claude Code is an agentic coding tool. From 0.2.54 until 2.1.163, because the hostname huggingface.co was pre-approved as a bare hostname for the WebFetch tool, any path on that domain—including attacker-controlled model repositories—was auto-approved without a permission prompt or being subject to --allowedTools restrictions. An attacker able to inject untrusted content into a Claude Code context could direct it to issue WebFetch requests against attacker-controlled repository files (e.g. /resolve/main/config.json), which HuggingFace counts as downloads server-side, creating a covert out-of-band channel for encoding and exfiltrating data Claude can access such as files, environment variables, or command output. Reliably exploiting this required the ability to add untrusted content into a Claude Code context window. This vulnerability is fixed in 2.1.163. | |
| Title | Claude Code: Out-of-Band Data Exfiltration via Pre-Approved HuggingFace Domain in WebFetch | |
| Weaknesses | CWE-183 CWE-200 CWE-515 |
|
| References |
| |
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-06-23T17:37:38.468Z
Reserved: 2026-06-12T18:42:02.223Z
Link: CVE-2026-54316
Updated: 2026-06-23T17:37:34.873Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-23T20:00:07Z
Github GHSA