Permissive List of Allowed Inputs in Claude Code - CVE-2026-54316
Published: June 18, 2026
Vulnerability identifier: #VU134813
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-54316
CWE-ID: CWE-183
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Anthropic
Affected software:
Claude Code
Claude Code
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to a permissive allowlist in the WebFetch tool when processing requests to pre-approved huggingface.co paths. A remote attacker can inject untrusted content into a Claude Code context to trigger WebFetch requests to attacker-controlled repository files and disclose sensitive information.
Exploitation requires the ability to add untrusted content into a Claude Code context window, and the issue creates a covert out-of-band exfiltration channel through server-side download requests.
How to mitigate CVE-2026-54316
Install security update from vendor's website.