JGraph draw.io up to 30.2.6 OAuth Callback AbsAuth.java improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in JGraph draw.io up to 30.2.6. Impacted is an unknown function of the file src/main/java/com/mxgraph/online/AbsAuth.java of the component OAuth Callback Handler. Performing a manipulation results in improper authorization. This vulnerability is identified as CVE-2026-63373. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in JGraph draw.io up to 30.2.6. This affects an unknown functionality of the file src/main/java/com/mxgraph/online/AbsAuth.java of the component OAuth Callback Handler. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

draw.io is a configurable diagramming and whiteboarding application. Prior to version 30.2.7, the OAuth callback handler in src/main/java/com/mxgraph/online/AbsAuth.java skips comparison of stateToken and cookieToken whenever IS_GAE is false, which affects self-hosted Docker and WAR deployments. An attacker can provide an authorization code for the attacker's cloud-storage identity and induce a victim to visit a callback URL, causing the victim's draw.io session to become authenticated as the attacker identity without a valid state binding. The shared handler affects Google Drive, OneDrive, GitHub, GitLab, and Dropbox integrations. The victim can then unknowingly perform cloud-storage actions under the attacker's identity, causing session integrity loss and misattribution, but the identity binding does not itself grant access to existing victim cloud files. This issue is fixed in version 30.2.7.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-63373 since 07/16/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

Upgrading to version 30.2.7 eliminates this vulnerability.

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Productinfo

Vendor

• JGraph

Name

• draw.io

Version

• 30.2.0
• 30.2.1
• 30.2.2
• 30.2.3
• 30.2.4
• 30.2.5
• 30.2.6

License

• open-source

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