---
cve: "CVE-2026-100868"
severity: "MEDIUM"
cvss: 5.3
epss: "0.3%"
vendor: "penpot"
kev: false
exploited: false
published: "2026-09-27 13:09:53"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-10-05T03:13:22+02:00"
---

# CVE-2026-100868

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

Penpot before 2.18.0 binds the MCP server plugin WebSocket bridge to all network interfaces without authentication in single-user mode. Unauthenticated attackers on adjacent networks can connect to the WebSocket port to impersonate the Penpot browser plugin, intercept task payloads, and return forged results to the MCP client.

## CNA-Record (Kanon, cvelistV5)

- CNA: **VulnCheck**
- State: PUBLISHED
- Stand: 2026-09-28 15:40:09
- CNA-CVSS: **5.3** (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

```
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Benachbart | warn |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 5baffdc213f0deaaeb318e97a41d611ac0656a94 (Commit)

## Referenzen

- <https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r>
- <https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddeb>
- <https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/mcp/packages/server/src/PluginBridge.ts#L52>
- <https://github.com/penpot/penpot/security/advisories/GHSA-22qr-rp27-j9wm>
- <https://github.com/penpot/penpot>
- <https://www.vulncheck.com/advisories/penpot-before-2.18.0-unauthenticated-websocket-access-via-mcp-bridge>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-100868) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_