CVE-2026-63334 draw.io: SSRF via DNS rebinding in ProxyServlet bypasses private IP blocklist
Attackers can exploit DNS rebinding in the proxy feature to access internal services and cloud metadata, requiring the proxy feature to be enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-63334?
CVE-2026-63334 is a medium-severity server-side request forgery vulnerability in jgraph drawio, published on 21 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-63334?
How do I fix CVE-2026-63334?
No fix has been published for CVE-2026-63334 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-63334 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-63334 exists.
Sources
Also known as GHSA-3v4h-8r2c-m8c5.