CVE-2026-54618

CRITICAL 9.4CVE-2026-54618 · Published 17/09/2026 · updated 30/09/2026

In short

CVE-2026-54618 is a CRITICAL (CVSS 9.4) vulnerability.
Chance of exploitation in the next 30 days (EPSS): 0.51%, higher than 43.3% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
—	No affected product versions are listed for this vulnerability yet.

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.

References

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