VulnerabilityReceived

CVE-2026-54618

Obsidian Web MCP is a secure remote MCP server for Obsidian vaults.

CRITICAL 9.4EPSS 0.40%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 9.4 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS: 0.40% probability · 34th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-306, CWE-522, CWE-601
Source: security-advisories@github.com

EPSS trend

EPSS 0.4% since 19 September 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.