CVE-2026-100868

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.

CVSS 4.0

5.3CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

6.3CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

EPSS

0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-25)

CWE

CWE-1327

Published

2026-09-27

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

References

• https://github.com/penpot/penpot
• https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/mcp/packages/server/src/PluginBridge.ts#L52
• https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddeb
• https://github.com/penpot/penpot/security/advisories/GHSA-22qr-rp27-j9wm
• https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r

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