---
cve: "CVE-2026-54618"
severity: "CRITICAL"
cvss: 9.4
epss: "0.5%"
vendor: "jimprosser"
kev: false
exploited: false
published: "2026-09-17 20:16:51"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-10T18:36:10+01:00"
---

# CVE-2026-54618

> 9.4 CRITICAL · 🧪 PoC

## Beschreibung

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.

## CNA-Record (Kanon, cvelistV5)

- CNA: **GitHub_M**
- State: PUBLISHED
- Stand: 2026-09-24 20:40:37
- CNA-CVSS: **9.4** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Gering | warn |

## Schwachstellen-Klasse

- **CWE-306** — Missing Authentication for Critical Functionality
  The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
- **CWE-522** — Insufficiently Protected Credentials
  The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
- **CWE-601** — URL Redirection to Untrusted Site
  The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.

## Angriffsmuster (CAPEC)

- [CAPEC-12 — Choosing Message Identifier](https://capec.mitre.org/data/definitions/12.html) _(Severity: High)_
- [CAPEC-36 — Using Unpublished Interfaces or Functionality](https://capec.mitre.org/data/definitions/36.html) _(Severity: High)_
- [CAPEC-62 — Cross Site Request Forgery](https://capec.mitre.org/data/definitions/62.html) _(Severity: Very High)_
- [CAPEC-166 — Force the System to Reset Values](https://capec.mitre.org/data/definitions/166.html) _(Severity: Medium)_
- [CAPEC-216 — Communication Channel Manipulation](https://capec.mitre.org/data/definitions/216.html)

## Patch verfügbar (OSV)

- e4924f096ee7494a7999d6c0cceca9be08e48eef (Commit)

## Referenzen

- <https://github.com/jimprosser/obsidian-web-mcp/security/advisories/GHSA-hwhg-mrjc-8g43>
- <https://github.com/jimprosser/obsidian-web-mcp/pull/30>
- <https://github.com/jimprosser/obsidian-web-mcp/commit/e4924f096ee7494a7999d6c0cceca9be08e48eef>
- <https://github.com/jimprosser/obsidian-web-mcp/releases/tag/v0.2.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-54618/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_