CVE-2026-100868
Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge
- State
- Published
- Severity
- 5.3 Medium
- Published
- Sep 27, 2026
- Updated
- Oct 8, 2026
- Reserved
- Sep 27, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.3 Medium | 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 | VulnCheck |
| 3.1 | 6.3 Medium | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L | VulnCheck |
Weaknesses
- CWE-1327 Binding to an Unrestricted IP Address
Affected Products
| Product | Versions |
|---|---|
penpotpenpot |
|
@penpot/mcppenpot |
|
References
- GitHub Security Advisory (GHSA-ch2q-6x56-qg5r)vendor-advisory
- https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddebpatch
- https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/mcp/packages/server/src/PluginBridge.ts#L52technical-description
- GitHub Security Advisory (GHSA-22qr-rp27-j9wm)relatedvendor-advisory
- https://github.com/penpot/penpotproduct
- VulnCheck Advisory: Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridgethird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.