SSRF in Jgraph Drawio
CVE-2026-63334
draw.io is a configurable diagramming and whiteboarding application. Prior to version 30.2.7, deployments with ENABLE_DRAWIO_PROXY=1 are vulnerable to server-side request forgery because src/main/java/com/mxgraph/online/Utils.java performs the private-address check in Utils.sanitizeUrl() using one DNS resolution, while src/main/java/com/mxgraph/online/ProxyServlet.java later calls URL.openConnection() and performs a second resolution. An attacker-controlled hostname can resolve to a public address during validation and then to a private, link-local, or cloud metadata address when the connection is opened. Successful exploitation can return cloud instance metadata or responses from internal HTTP services through the proxy. This issue is fixed in version 30.2.7.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N.
Affected products
- Jgraph Drawio — versions < 30.2.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-63334?
- CVE-2026-63334 is a medium-severity vulnerability in Jgraph Drawio, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.8/10. Published 2026-09-21.
- How severe is CVE-2026-63334?
- Medium severity. CVSS v3 base score is 6.8 out of 10.