CVE-2026-54618 (GCVE-0-2026-54618)

Vulnerability from cvelistv5 – Published: 2026-09-17 19:45 – Updated: 2026-09-24 20:40
VLAI
Title
Obsidian Web MCP: Unauthenticated vault access: /oauth/authorize auto-approves without authenticating the user
Summary
Obsidian Web MCP is a secure remote MCP server for Obsidian vaults. Prior to 0.2.0, /oauth/authorize issues an authorization code without a login, consent, or session check, and /oauth/token can exchange that code for the static VAULT_MCP_TOKEN without authenticating a client. An unauthenticated remote caller who can reach the intended tunnel deployment can therefore call /mcp and use vault_read, vault_write, vault_search, vault_list, vault_move, and vault_delete against the entire vault. Optional PKCE does not prevent an attacker-initiated flow, and unauthenticated /oauth/register also exposes a client_credentials path by returning the configured VAULT_OAUTH_CLIENT_SECRET. This issue is fixed in version 0.2.0.
Severity
9.4 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
SSVC
Exploitation: poc Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 20:40 UTC
CWE
  • CWE-306 - Missing Authentication for Critical Function
  • CWE-522 - Insufficiently Protected Credentials
  • CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7846 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
jimprosser obsidian-web-mcp Affected: < 0.2.0
guessed Create a notification for this product.
Show details on NVD website
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