draw.io: Stored XSS on file open via editable=0 sibling cell — patch bypass of CVE-2026-46642

draw.io is a configurable diagramming and whiteboarding application. Prior to version 30.2.5, opening or importing a crafted .drawio file can execute attacker-controlled JavaScript in the draw.io origin when selected cells are processed by TextFormatPanel.addFont() in src/main/webapp/js/grapheditor/Format.js. An HTML sibling cell keeps the formatted-label path enabled while an editable=0 plain-text sibling is excluded from the merged selection style but remains in the iteration set. graph.cellRenderer.getLabelValue() returns that plain-text label without HTML encoding, and mxUtils.canConvertHtmlToSvg() parses it as HTML, bypassing the earlier CVE-2026-46642 remediation. Successful exploitation can expose diagram data, browser storage, non-HttpOnly cookies, and same-origin actions available to the victim. This issue is fixed in version 30.2.5.

Source published

21 Sep 2026 16:15:30 UTC

Source modified

29 Sep 2026 15:05:34 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N