CVE-2026-100868 PUBLISHED

Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge

Assigner: VulnCheck
Reserved: 27.09.2026 Published: 27.09.2026 Updated: 27.09.2026

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 Vector: 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
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Adjacent	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	Low	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

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

Attack Vector	Adjacent Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	Low

CVSS 3.1

Product Status

Vendor	penpot
Product	penpot
Versions	Default: unaffected affected from 0 to 2.18.0 (excl.)

Vendor	penpot
Product	@penpot/mcp
Versions	Default: unaffected affected from 0 to 2.15.4 (incl.)

CVE-2026-100868 PUBLISHED

Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge

Metrics

Product Status

Credits

References

Problem Types