{"id":"CVE-2026-100868","aliases":["EUVD-2026-87940","GHSA-hm3w-7xgf-hfwf"],"status":"published","title":"Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge","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.","severity":{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00535,"percentile":0.45613,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1327"],"published":"2026-09-27T13:09:53Z","modified":"2026-10-28T02:31:12Z","products":[{"vendor":"penpot","product":"@penpot/mcp"},{"vendor":"penpot","product":"penpot"}],"references":[{"url":"https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r","tags":["vendor-advisory","exploit","advisory"]},{"url":"https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddeb","tags":["patch","fix"]},{"url":"https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/mcp/packages/server/src/PluginBridge.ts#L52","tags":["technical-description","article"]},{"url":"https://github.com/penpot/penpot/security/advisories/GHSA-22qr-rp27-j9wm","tags":["related","vendor-advisory","advisory"]},{"url":"https://github.com/penpot/penpot","tags":["product","package"]},{"url":"https://www.vulncheck.com/advisories/penpot-before-2.18.0-unauthenticated-websocket-access-via-mcp-bridge","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100868","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hm3w-7xgf-hfwf"},{"url":"https://www.npmjs.com","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100868.json","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-100868","title":"Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge","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.","status":"published","published":"2026-09-27T13:09:53.387Z","modified":"2026-10-08T15:22:06.862Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-1327"],"updated_at":"2026-11-02T14:20:06.925367Z"}],"euvd":[{"id":"EUVD-2026-87940","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.","status":"published","published":"2026-09-27T13:09:53Z","modified":"2026-10-08T15:22:06Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"updated_at":"2026-11-02T17:27:32.18003Z"}],"ghsa":[{"id":"GHSA-hm3w-7xgf-hfwf","title":"Penpot before 2.18.0 binds the MCP server plugin WebSocket bridge to all network interfaces...","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.","status":"published","published":"2026-09-27T15:31:07Z","modified":"2026-09-27T15:31:08Z","cvss":[{"version":"4.0","score":5.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-1327"],"updated_at":"2026-11-02T15:12:30.689958Z"}],"nvd":[{"id":"CVE-2026-100868","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.","status":"published","published":"2026-09-27T13:16:37.96Z","modified":"2026-10-08T16:17:00.783Z","cvss":[{"version":"4.0","score":5.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-1327"],"updated_at":"2026-11-02T14:12:52.081323Z"}],"osv":[{"id":"CVE-2026-100868","title":"Penpot before 2.18.0 Unauthenticated WebSocket Access via MCP Bridge","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.","status":"published","published":"2026-09-27T13:09:53.387Z","modified":"2026-10-28T02:31:12.861490176Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"cwes":["CWE-1327"],"updated_at":"2026-11-02T15:44:53.83521Z"}]}}