Description
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.
Published: 2026-09-17
Score: 9.4 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Thu, 17 Sep 2026 20:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Obsidian Web MCP: Unauthenticated vault access: /oauth/authorize auto-approves without authenticating the user
Weaknesses CWE-306
CWE-522
CWE-601
References
Metrics cvssV3_1

{'score': 9.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L'}

Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-17T19:45:15.384Z

Reserved: 2026-06-15T20:07:02.184Z

Link: CVE-2026-54618

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-17T20:16:51.823

Modified: 2026-09-17T20:16:51.823

Link: CVE-2026-54618

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-306

    Missing Authentication for Critical Function

  • CWE-522

    Insufficiently Protected Credentials

  • CWE-601

    URL Redirection to Untrusted Site ('Open Redirect')