CVE-2026-58504 jgraph CVE debrief

Who should care

Defenders responsible for draw.io installations, as well as users who open or import .drawio files from untrusted sources, should be aware of this vulnerability and take steps to mitigate it.

Why it matters

CVE-2026-58504 is a medium-severity vulnerability in draw.io that allows for the execution of attacker-controlled JavaScript when a crafted .drawio file is opened or imported. Defenders should prioritize updating to version 30.2.5 or later and be cautious when opening or importing .drawio files from untrusted sources.

• Exposure of diagram data to unauthorized parties
• Potential theft of browser storage and non-HttpOnly cookies
• Execution of same-origin actions available to the victim

Technical summary

The vulnerability is caused by the application's failure to properly handle crafted .drawio files, allowing for the execution of attacker-controlled JavaScript when selected cells are processed by TextFormatPanel.addFont() in src/main/webapp/js/grapheditor/Format.js. Successful exploitation can expose diagram data, browser storage, non-HttpOnly cookies, and same-origin actions available to the victim. The issue is fixed in version 30.2.5. Defenders should prioritize updating to version 30.2.5 or later and be cautious when opening or importing .drawio files from untrusted sources.

Defensive priority

Defenders should prioritize updating to version 30.2.5 or later to mitigate this vulnerability. They should also be cautious when opening or importing .drawio files from untrusted sources.

Recommended defensive actions

• Update to version 30.2.5 or later
• Be cautious when opening or importing .drawio files from untrusted sources
• Monitor for suspicious activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by the application's failure to properly handle crafted .drawio files, allowing for the execution of attacker-controlled JavaScript. This issue is fixed in version 30.2.5. Defenders should verify the integrity of .drawio files and be cautious when opening or importing files from untrusted sources. The CVE record was published on 2026-09-21T17:17:36.077Z and has not been modified since then. The vulnerability has a CVSS score of 6.1 and a severity of MEDIUM.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.