CVE-2026-54316 (GCVE-0-2026-54316)

Vulnerability from cvelistv5 – Published: 2026-06-23 17:06 – Updated: 2026-06-23 17:37
VLAI
Title
Claude Code: Out-of-Band Data Exfiltration via Pre-Approved HuggingFace Domain in WebFetch
Summary
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.
Severity
6 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-23 17:37 UTC
CWE
  • CWE-183 - Permissive List of Allowed Inputs
  • CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-515 - Covert Storage Channel
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7831 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
anthropics claude-code Affected: >= 0.2.54, < 2.1.163
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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