CVE-2026-42195: Unvalidated gitlab URL parameter redirects OAuth authorize step to attacker-controlled host
draw.io is a configurable diagramming and whiteboarding application. Prior to version 29.7.9, the draw.io client accepts a ?gitlab= URL parameter that overrides the GitLab server URL used during OAuth sign-in. A crafted link causes the user's click on draw.io's "Authorize in GitLab" dialog to open a popup on the attacker-controlled host instead of gitlab.com. This can lead to credential fishing and session state token exfiltration. This issue has been patched in version 29.7.9.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42195?
CVE-2026-42195 has been classified as a high-severity vulnerability due to the potential for unauthorized access during OAuth authentication.
How do I fix CVE-2026-42195?
To mitigate CVE-2026-42195, users should upgrade to draw.io version 29.7.9 or later to ensure the unsafe URL parameter is no longer accepted.
What systems are affected by CVE-2026-42195?
CVE-2026-42195 affects the draw.io application versions prior to 29.7.9.
What impact does CVE-2026-42195 have on users?
CVE-2026-42195 allows attackers to redirect users to malicious sites during the OAuth authorization process, potentially leading to credential theft.
What should organizations do regarding CVE-2026-42195?
Organizations should review their use of draw.io and ensure that they are on version 29.7.9 or later to avoid exploitation of CVE-2026-42195.