{"id":"CVE-2026-100868","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100868","generatedAt":"2026-10-28T05:28:11.379Z","title":"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.","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.","published":"2026-09-27T13:16:38.000Z","lastModified":"2026-10-08T16:17:01.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","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/M"},"cwe":["CWE-1327"],"affected":[],"epss":{"score":0.00535,"percentile":0.44919,"date":"2026-10-27","history":[{"date":"2026-09-28","score":0.00257,"percentile":0.15652}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.53%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-27T13:16:38.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-09-27T13:16:37.960Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/penpot/penpot","source":"disclosure@vulncheck.com"},{"url":"https://github.com/penpot/penpot/blob/1d2c37e52c733f74017d90b0fd1ae2d074a5c33d/mcp/packages/server/src/PluginBridge.ts#L52","source":"disclosure@vulncheck.com"},{"url":"https://github.com/penpot/penpot/commit/b5274a44766d095247037be18c1d1918ac67ddeb","source":"disclosure@vulncheck.com"},{"url":"https://github.com/penpot/penpot/security/advisories/GHSA-22qr-rp27-j9wm","source":"disclosure@vulncheck.com"},{"url":"https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/penpot-before-2.18.0-unauthenticated-websocket-access-via-mcp-bridge","source":"disclosure@vulncheck.com"},{"url":"https://github.com/penpot/penpot/security/advisories/GHSA-ch2q-6x56-qg5r","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100868","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}