What’s Vulnerable › Vulnerabilities

CVE-2026-58504: draw.io: Stored XSS on file open via editable=0 sibling cell — patch bypass of CVE-2026-46642

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-21 · updated 2026-09-29
• Weakness: CWE-79

Description

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.

Affected products

• jgraph/drawio: before 30.2.5

References

• https://github.com/jgraph/drawio/commit/7976c02e1b10b1687c028d82782f9f5d90a885d6
• https://github.com/jgraph/drawio/releases/tag/v30.2.5
• https://github.com/jgraph/drawio/security/advisories/GHSA-c76x-r78m-phwx
• https://github.com/jgraph/drawio/security/advisories/GHSA-c76x-r78m-phwx

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