makeplane Plane up to 1.3.x Gitea OAuth validate_url GITEA_HOST/avatar_url server-side request forgery

Summaryinfo

A vulnerability, which was classified as critical, has been found in makeplane Plane up to 1.3.x. Affected is the function validate_url of the component Gitea OAuth. The manipulation of the argument GITEA_HOST/avatar_url leads to server-side request forgery. This vulnerability is uniquely identified as CVE-2026-104976. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in makeplane Plane up to 1.3.x. This issue affects the function validate_url of the component Gitea OAuth. The manipulation of the argument GITEA_HOST/avatar_url with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Plane is an open-source project management tool. Prior to 1.4.0, Plane validates GITEA_HOST only for its URL scheme and does not reject hosts that resolve to private or internal IP addresses. The four outbound requests in the Gitea OAuth flow are derived from this unvalidated host and do not call validate_url(). In addition, avatar_url is taken from the Gitea user's profile, where users can configure external avatar URLs. After an administrator enables Gitea OAuth for a legitimate instance, a Gitea user can set an internal URL as the profile avatar and log in through Gitea, causing Plane to fetch the internal target without validation. This issue is fixed in 1.4.0.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-104976 since 10/02/2026. The exploitation is known to be easy. The attack may be initiated remotely. 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.

Upgrading to version 1.4.0 eliminates this vulnerability.

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Productinfo

Vendor

• makeplane

Name

• Plane

Version

• 1.0
• 1.1
• 1.2
• 1.3

Website

• Product: https://github.com/makeplane/plane/

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