Claude Code: Insecure System-Wide Configuration Loading Enables Local Privilege Escalation on Windows

On Windows, Claude Code loaded system-wide default configuration from `C:\ProgramData\ClaudeCode\managed-settings.json` without validating directory ownership or access permissions. Because the `ProgramData` directory is writable by non-administrative users by default and the `ClaudeCode` subdirectory was not pre-created or access-restricted, a low-privileged local user could create this directory and place a malicious configuration file that would be automatically loaded for any user launching Claude Code on the same machine. Exploiting this would have required a shared multi-user Windows system and a victim user to launch Claude Code after the malicious configuration was placed. Users on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to the latest version. Thank you to hackerone.com/edbr for reporting this issue.

Source published

17 Apr 2026 22:19:38 UTC

Source modified

5 May 2026 16:04:01 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

CVSS_V4 · CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Publisher rating · MODERATE